COSC 236 Section 101

COSC 236 Section 101Computer Science 1 -- Prof. Michael A. Soderstrand

COSC 236 Web Site

• You will always find the course material at:

http://www.class-notes.us or

http://www.class-notes.info or

http://www.lecture-notes.tripod.com

From this site you can click on the COSC-236 tab to download the PowerPoint lectures, the Quiz solutions and the Laboratory assignments.

COSC 236 :Prof. M.A. Soderstrand Lecture 26 12/01//2014

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http://www.class-notes.us/

http://www.class-notes.info/

http://www.lecture-notes.tripod.com/


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Review for Final Exam (Wednesday 12/17/14 3-5pm)

• The Final Exam will cover the entire course

• The Exam will be similar to the in-class portion of the Midterm

•You should review Lecture 13, the review for the Midterm

• This review will cover Lectures 14 through 25


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Review of Quiz 13


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Review of Quiz 13


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There are at least two ways to solve this problem using material

that we have covered in class so far:

• The one based on the material in Lecture 13 is to make use of a

for loop to implement a cumulative algorithm

• The algorithm is to copy character by character from text to

temp checking for when the loop counter i becomes equal to

index to trigger the insertion of newText

• After the new text is inserted, the remainder of text is copied

Review of Quiz 13


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public static String replaceAt(int index, String text, String newText) {

int length = text.length();

String temp = "";

if (index < 0 || index >= length) {return text; } //Check for out of range index

else {

for (int i = 0; i < length; i++) {

if (i == index) {temp = temp + newText; }

else {temp = temp + text.charAt(i);}

}

}

return temp;

}

Review of Quiz 13 (Complete Program 1)


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Review of Quiz 13


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There are at least two ways to solve this problem using material

that we have covered in class so far:

• The second technique is actually simpler, but is not based on

the material in Lecture 13 on cumulative algorithms

• The algorithm uses the substring method to specify the initial

text from text, then concatenate the newText, and finally use

the substring method to complete the text.

• This is a simpler method, but does not demonstrate the

cumulative algorithm we are studying.

Review of Quiz 13


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String temp = "";

if (index < 0 || index >= length) {return text;} //Check for out of range index

else {temp = text.substring(0, index) + newText + text.substring(index+1, length);}

return temp;

}

Review of Quiz 13 (Complete Program 2)


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import java.util.*; // for Scanner

public class Quiz13a {

public static void main(String[] args) {

Scanner console = new Scanner(System.in);

String text = "0123456789"; // This is the text that will be modified

System.out.println("\ntext to be modified = " + text);

System.out.print("Enter index of the character you wish to replace in the text: ");

int index = console.nextInt(); // Read index from console

console.nextLine(); // Clear the console for next read

System.out.println("\nEnter the String you wish to replace that character with: ");

String newText = console.nextLine(); // Read the new text

System.out.println();

text = replaceAt(index, text, newText); // Call the replace method

System.out.println("Modified text = " + text); // Print modified text to console

}



String temp = "";

if (index < 0 || index >= length) {return text;} //Check for out of range index

else {temp = text.substring(0, index) + newText + text.substring(index+1, length);} return temp;

}

}

Review of Quiz 14


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Review of Quiz 14


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This should be a very easy Quiz, if you approach it one line at a

time:

• First get the Heading of the table correct

• Then do one column at a time getting each column correct

before moving to the next

• After all columns are done, you have a completed program

Review of Quiz 14


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Start with the heading of the table:

Two approaches

• Use printf() with “%4s%12s %12s %12s %12s”

• Use printf() with the entire heading exactly in quotes:

“Year Yearly Quarterly Monthly Continuously”

Review of Quiz 14


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Use printf() with “%4s%12s %12s %12s %12s” :


public class Quiz14_1 {



System.out.print("Enter the principle (amount deposited.) P = ? ");

double p = console.nextDouble();

System.out.print("Enter the yearly interest rate. r = ? ");

double r = console.nextDouble();

r = r/100;

System.out.print("Enter the time in whole number of years. t = ? ");

int t = console.nextInt();

System.out.printf("\n%4s%12s %12s %12s %12s\n", "Year", "Yearly", "Quarterly", "Monthly", "Continuously");

}

}

Review of Quiz 14


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Use printf() with “%4s%12s %12s %12s %12s” :

Review of Quiz 14


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Use printf(“Year Yearly Quarterly Monthly Continuously”):









r = r/100;



System.out.printf("\nYear Yearly Quarterly Monthly Continuously\n");

}

}

Review of Quiz 14


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Get the first column to line up:import java.util.*; // for Scanner








r = r/100;




for (int n = 1; n <= t; n++) {

System.out.printf("%2d", n);


}

}

}

Review of Quiz 14


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Get the first column to line up:

Review of Quiz 14


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Get the second column to line up:import java.util.*; // for Scanner








r = r/100;




for (int n = 1; n <= t; n++) {


System.out.printf(" $%,9.2f", p*Math.pow(1+r,n));


}

}

}

Review of Quiz 14


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Get the second column to line up:

Review of Quiz 14


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Get the third column to line up:import java.util.*; // for Scanner








r = r/100;




for (int n = 1; n <= t; n++) {



System.out.printf(" $%,9.2f", p*Math.pow(1+r/4,4*n));


}

}

}

Review of Quiz 14


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Get the third column to line up:

Review of Quiz 14


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Get the fourth column to line up:import java.util.*; // for Scanner








r = r/100;




for (int n = 1; n <= t; n++) {






}

}

}

Review of Quiz 14


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Get the fourth column to line up:

Review of Quiz 14


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Get the last (5th) column to line up:import java.util.*; // for Scanner








r = r/100;




for (int n = 1; n <= t; n++) {

System.out.printf("%2d", n); //1st column

System.out.printf(" $%,9.2f", p*Math.pow(1+r,n)); //2nd column

System.out.printf(" $%,9.2f", p*Math.pow(1+r/4,4*n)); //3rd column

System.out.printf(" $%,9.2f", p*Math.pow(1+r/12,12*n)); //4th column

System.out.printf(" $%,9.2f", p*Math.pow(Math.E,r*n)); //5th column


}

}

}

Review of Quiz 14


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Get the last (5th) column to line up:

Review of Quiz 15


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Quiz 15: This Quiz is aimed at using random numbers and printing out a list separated by commas using the fencepost algorithm discussed in Lecture 14.

Write a complete program (class) that asks the user how many random numbers the user wants printed and then prints on a single line that number of random numbers. The random numbers will be integers in the range 2 through 12 inclusive. Each random number is separated by a comma and a space.

Here is what typical output from your program will look like:

NOTE: There should be no extra commas or spaces at the beginning or at the end of the list.

Review of Quiz 15


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There are two issues addressed in Quiz 15:

• First is generating random integers between 2 and 12 inclusively

• The range is max – min + 1 = 12 – 2 + 1 = 11

• The minimum number is 2

• rand.nextInt(11) + 2

• The second is the fence-post algorithm to print out the random numbers with commas

between each number

• Print one random number before the for loop and leading commas in the for loop

• Print following commas in the for loop and one random number after the for loop

Review of Quiz 15


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public class Quiz15 {


Random rand = new Random();


System.out.print("How many random numbers would you like? ");

int number = console.nextInt();

System.out.print(rand.nextInt(11) + 2);

for (int n = 1; n <= number; n++) {

System.out.print(", " + (rand.nextInt(11) +2));

}


}

}

Boiler Plate

Set up random numbersSet up scanner for input

Prompt and get inputPrint first fence post

Print line of number preceded by comma and spaceUse println to go to next line at end of program

Review of Quiz 15


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QUESTION about the random numbers generated in Quiz 15:

• Would these number represent the throw of two dice?

• The range is correct: min = 2, max = 12

• The numbers are random

• Does rand.nextInt(11) + 2 simulate the roll of two

dice?

• NO: The numbers 2 through 12 are not equally likely!

Review of Quiz 15


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QUESTION about the

random numbers

generated in Quiz 15:

• Would these number

represent the throw of

two dice?

• NO: The numbers 2

through 12 are not

equally likely!

rand.nextInt(6) + rand.nextInt(6) + 2

Review of Quiz 16


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You were given the main program and were asked to write the two Boolean methods isPrime() and hasAnEvenDigit()

The method isPrime() was already written for you –although you were asked to improve it

The method hasAnEvenDigit() can be obtained by making modifications to hasAnOddDigit()

Review of Quiz 16


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There are two issues addressed in Quiz 16:

• Modifying the ifPrime() method to make it more efficient

• Instead of the for loop going from 1 to n, it could go from 2 to n-1. The return

would then be changed to return factors == 0;

• The loop could run from 2 to n-1, but as soon as you found an integer that divided

into n, you would return a false so that it would not continue checking.

• The most efficient is to change the loop to run from 2 to Math.sqrt(n) and to return

a false as soon as you find an integer that divided into n

• Modifying hasAnOddDigit() to check for even digits.

• Change the statement if (n % 2 != 0) to if (n % 2 == 0)

Review of Quiz 16


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public static boolean isPrime(int n) {

n = Math.abs(n); // take care of negative numbers

for (int i = 2; i*i <= n; i++) {

if (n % i == 0) {

return false;

}

}

Could also be: i <= Math.sqrt(n)

Review of Quiz 16


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public static boolean hasAnEvenDigit(int n) {

n = Math.abs(n); // take care of negative numbers

while (n > 0) {

if (n % 2 == 0) { // check whether last digit is even

return true;

}

n = n / 10;

}

return false;

}

Review of Quiz 17


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PART 1: You were given the program and asked to modify it to read the file Quiz17.java

You were to run the file and confirm the output as shown.

You were encouraged to copy and paste the program from the Quiz 17 assignment sheet.

Review of Quiz 17


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PART 1: Only one minor change required:

import java.io.*; // for File

import java.util.*; // Java utilities

public class FileRead {

public static void main(String[] args) throws FileNotFoundException {

File f = new File("Test.txt");

Scanner input = new Scanner(f);

System.out.println("exists returns " + f.exists());

System.out.println("canRead returns " + f.canRead());

System.out.println("length returns " + f.length());

System.out.println("getAbsolutePath returns "

+ f.getAbsolutePath());

int count = 0;

while (input.hasNext()) {

String word = input.next();

count++;

}

System.out.println("total words = " + count);

}

}

Change "Test.txt" to "Quiz17.java"

Review of Quiz 17


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PART 1: Only one minor change required:





File f = new File("Test.txt");







int count = 0;



count++;

}


}

}





File f = new File(“Quiz17.java);







int count = 0;



count++;

}


}

}

Change "Test.txt" to "Quiz17.java"

Review of Quiz 17


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PART 2: Modify the program to print out any comment lines and exclude them from the count

In class you were also told to add a comment at the beginning of the program:

// Report some basic information about a file.

Review of Quiz 17


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// Report some basic information about a file.





File f = new File("Quiz17.java");







ADD Comment

Change file name

Review of Quiz 17


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int count1 = 0;

int count2 = 0;



if (word.equals("//")) {

count2++;

String temp = input.nextLine();

System.out.println("Comment " + count2 + " = //" + " " + temp);}

else {count1++;}

}

System.out.println("total words excluding comments = " + count1

+ "\nThere are " + count2 + " comments.");

}

}

Set up counter for comments

Set up counter for words

Check token for comment

Review of Quiz 17


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int count1 = 0;

int count2 = 0;



if (word.equals("//")) {

count2++;


System.out.println("Comment " + count2 + " = //" + " " + temp);}

else {count1++;}

}

System.out.println("total words excluding comments = " + count1

+ "\nThere are " + count2 + " comments.");

}

}

Increment comment counter

The rest of the line is comment

Print out comment number and comment

If not a comment, increment word counter

No change in the rest of the program

Review of Quiz 18


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PART 1: Insert a while loop that allows the user to query whether or not a file exist (“q” to quit)

PART2: Insert a second while loop to print out the summary which was stored in a file in the first while loop

You were encouraged to copy and paste the program from the Quiz 18 assignment sheet.

Review of Quiz 18


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PART 1: First while loop:

while (!name.equals("q")) {

File f = new File(name);

if (f.exists()) {

consoleOut.printf("File %s exists.\n", name);

file.printf("File %s exists.", name);

file.println();}

else {

consoleOut.printf("File %s DOES NOT exist.\n", name);

file.printf("File %s DOES NOT exist.", name);

file.println();}

Review of Quiz 18


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while (summary.hasNextLine()) {

String line = summary.nextLine();

consoleOut.println(line);

}

PART 2: Second while loop:

Review of Quiz 19


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User enters the number of test scores and then is prompted to enter each test score

Program calculates the mean, median, high and low score

The Weather Program of Lecture 18, slide 42 does most of what is needed. We need only to replace the day’s above average loop with the calculation of low, high and median

Review of Quiz 19


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The Weather Program:// Reads temperatures from the user, computes average and # days above average.

import java.util.*;

public class Weather {



System.out.print("How many days' temperatures? ");

int days = console.nextInt();

double[] temps = new double[days]; // array to store days' temperatures

double sum = 0;

for (int i = 0; i < days; i++) { // read/store each day's temperature

System.out.print("Day " + (i + 1) + "'s high temp: ");

temps[i] = console.nextDouble();

sum += temps[i];}

double average = sum / days;

int count = 0; // see if each day is above average

for (int i = 0; i < days; i++) {

if (temps[i] > average) {

count++;}

}

// report results

System.out.printf("Average temp = %.1f\n", average);

System.out.println(count + " days above average");

}

}

Arrays.sort(temps);

double median = 0;

if (temps.length % 2 == 1) {median = temps[temps.length/2];}

else {

median = (temps[temps.length/2] + temps[temps.length/2 - 1])/2;

}

System.out.printf(" High Score: %6.2f\n Mean Score: %6.2f\n", temps[temps.length-1], average);

System.out.printf("Median Score: %6.2f\n Low Score: %6.2f\n", median, temps[0]);

Replace this

Review of Quiz 19


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The Weather Program:// Reads temperatures from the user, computes average and # days above average.

import java.util.*;

public class Weather {



System.out.print("How many days' temperatures? ");

int days = console.nextInt();

double[] temps = new double[days]; // array to store days' temperatures

double sum = 0;

for (int i = 0; i < days; i++) { // read/store each day's temperature

System.out.print("Day " + (i + 1) + "'s high temp: ");

temps[i] = console.nextDouble();

sum += temps[i];}

double average = sum / days;

int count = 0; // see if each day is above average

for (int i = 0; i < days; i++) {

if (temps[i] > average) {

count++;}

}

// report results

System.out.printf("Average temp = %.1f\n", average);

System.out.println(count + " days above average");

}

}

Arrays.sort(temps);

double median = 0;

if (temps.length % 2 == 1) {median = temps[temps.length/2];}

else {

median = (temps[temps.length/2] + temps[temps.length/2 - 1])/2;

}

System.out.printf(" High Score: %6.2f\n Mean Score: %6.2f\n", temps[temps.length-1], average);

System.out.printf("Median Score: %6.2f\n Low Score: %6.2f\n", median, temps[0]);

Review of Quiz 19


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OUTPUT:

We need only to modify the prompts to get the desired output

Review of Quiz 19


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Complete Program:// Reads test scores and calculates high, low, mean and median

import java.util.*;




System.out.print("How many test scores do you wish to enter? ");


double[] scores = new double[number]; // array to store scores

double sum = 0;

for (int i = 0; i < number; i++) { // read/store each score

System.out.print("Please enter test " + (i + 1) + "'s score: ");

scores[i] = console.nextDouble();

sum += scores[i];}

double mean = sum / number;

Arrays.sort(scores);

double high = scores[number-1];

double low = scores[0];

double median = 0;

if(number%2 == 0) {

median = (scores[number/2] + scores[number/2 - 1])/2; }

else {

median = scores[number/2]; }

// report results

System.out.printf("Test Statistics:\n");

System.out.printf(" High Score: %6.2f\n", high);

System.out.printf(" Mean Score: %6.2f\n", mean);

System.out.printf(" Median Score: %6.2f\n", median);

System.out.printf(" Low Score: %6.2f\n", low);

}

}

Review of Quiz 19


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Complete Program:// Reads test scores and calculates high, low, mean and median

import java.util.*;







double sum = 0;




sum += scores[i];}





double median = 0;

if(number%2 == 0) {


else {


// report results






}

}

Review of Quiz 20


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Use Quiz 19 as your model

Only the second part of Quiz 19 needs to be modified

You will print the array in the order it was entered using Arrays.toString

You will the use Arrays.sort to sort the array into ascending order and print it using Arrays.toString

Finally you will use your method to reverse the array and print the array in descending order using Arrays.toString

Review of Quiz 20


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The Program form Quiz 19:import java.util.*;







double sum = 0;




sum += scores[i];}





double median = 0;

if(number%2 == 0) {


else {


// report results






}

}

System.out.printf("Original array = %s\n", Arrays.toString(scores));


System.out.printf(" Sorted array = %s\n", Arrays.toString(scores));

System.out.printf("Reversed array = %s\n", Arrays.toString(reverse(scores)));

}

//Add your method to reverse the elements of an array

public static double[] reverse(double[] array) {

for (int i = 0; i < array.length/2; i++) {

double temp = array[i];

array[i] = array[array.length - i -1];

array[array.length - i -1] = temp;}

return array;

Replace this

Review of Quiz 20


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Replaced code:





}






return array;

}

Print original array Sort the array Print sorted array

Print the reversed array

The print statement contains the call to your method reverse that reverses the array

Review of Quiz 20


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Replaced code:





}






return array;

}

Accepts a double precision array as a parameter

Explicitly returns the reversed array to the main program

NOTE: The array passed by reference as a parameter has already been reversed. The explicit return allows us to use the method in a print statement.

Review of Quiz 20


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OUTPUT:

Printout verifies that the sort and reverse do work properly

Review of Quiz 21


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Use Quiz 20 as your model for the input dialogue

Set up the random numbers as specified in item 2, Quiz 21

The main program will use:int inversions = inversion(array);

To count the inversions.

Next calculate the percent

The main program prints out the array, inversions and percent

Finally, you need to write the method inversion to count the inversions (using Lecture 20 slide 65)

Review of Quiz 21


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The input dialogue:

import java.util.*;




System.out.print("How many random integers do you want? ");


double[] array = new double[number]; // array to store random numbers

System.out.print("What is the minimum number? ");

int min = console.nextInt();

System.out.print("What is the maximum number? ");

int max = console.nextInt();

int range = max - min +1;

1. Prompt for the size of the array

2. Get size from console andcreate the array

3. Prompt for minimum

4. Get minimum from console 5. Prompt for maximum

6. Get maximum from console 7. Set random numbers

Review of Quiz 21


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Complete the main program:

Random r = new Random();

for (int i = 0; i < number; i++) { // generate random number

array[i] = r.nextInt(range) + min;}

int inversions = inversion(array);

double percent = 200.0*inversions/number/(number-1);

System.out.printf("Original array = %s contains %d inversions

(%.1f%s).\n", Arrays.toString(array), inversions, percent, "%");

}

1. Create random object

2. Fill array with random numbers

3. Calculate inversions

4. Calculate percent

5. Print resultsNOTE: Trick to print out % in printf statement

Review of Quiz 21


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Method inversion():

public static int inversion(double[] data) {

int count = 0;

for (int i = 0; i < data.length - 1; i++) {

for (int j = i + 1; j < data.length; j++) {

if (data[i] > data[j]) {

count++;}

}

}

return count;

}

1. Returns integer (# of inversions)

2. Accepts an array

3. Initialize the inversion count

4. Optimized inversion algorithm

5. Returns inversion count

Review of Quiz 21


62

Complete Program:import java.util.*;

public class Quiz21 {public static void main(String[] args) {

Scanner console = new Scanner(System.in);System.out.print("How many random integers do you want? ");int number = console.nextInt();double[] array = new double[number]; // array to store random numbersSystem.out.print("What is the minimum number? ");int min = console.nextInt();System.out.print("What is the maximum number? ");int max = console.nextInt();int range = max - min +1;Random r = new Random();for (int i = 0; i < number; i++) { // generate random number

array[i] = r.nextInt(range) + min;}int inversions = inversion(array);double percent = 200.0*inversions/number/(number-1);System.out.printf("Original array = %s contains %d inversions (%.1f%s).\n", Arrays.toString(array), inversions, percent, "%");

} public static int inversion(double[] data) {

int count = 0;for (int i = 0; i < data.length - 1; i++) {

for (int j = i + 1; j < data.length; j++) {if (data[i] > data[j]) {

count++;}// System.out.println("(" + data[i] + ", " + data[j] + ")");}

}}return count;

}}

This program is suitable for copy and paste to DrJava

Review of Quiz 21


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OUTPUT:

This is the array of random numbers printed out using Arrays.toString()

This is the actual number of inversions in the array This is the percentage of inversions in the array

Review of Quiz 21


64

OUTPUT:

If the percent of inversions is 0%, the array is sorted in ascending order

If the percent of inversions is 100%, the array is sorted in descending order

This array is nearly a perfect random array (50% inversions)

With only 10 elements in the array, your results can vary greatly from the ideal 50%

Review of Quiz 22


65


Ask for number of rows, then setup array with columns blankdouble[][] array = new double[row][];

Review of Quiz 22


66


Ask for number of rows, then setup array with columns blank

Set up a for loop to enter the number of columns for each row and the column data

double[][] array = new double[row][];

for (int i =0; i < row; i++) {

System.out.printf("Row%3d: Enter number of columns

followed by values: ", i+1);

int col = console.nextInt();

array[i] = new double[col];

for (int j = 0; j < col; j++) {

array[i][j] = console.nextDouble();}

}

Review of Quiz 22


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System.out.printf("Row%3d: Enter number of columns

followed by values: ", i+1);



for (int j = 0; j < col; j++) {


}

After all data is entered, use the method from page 488 of the text to print out the whole array.

Review of Quiz 22


68






public static void print(double[][] grid) {

for (int i = 0; i < grid.length; i++) {

for (int j = 0; j < grid[i].length; j++) {

System.out.print(grid[i][j] + " ");}

System.out.println();}

}

Review of Quiz 22


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}

Review of Quiz 22


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import java.util.*;




System.out.print("How many rows do you want? ");

int row = console.nextInt();



System.out.printf("Row%3d: Enter number of columns followed by values: ", i+1);



for (int j = 0; j < col; j++) {


}


print(array);

}






}

}

Review of Quiz 23


71

Use Lecture 22 Slide 42 as your starting point

Review of Quiz 23


72


Replace the System.out.println() statement with:

System.out.println("Deal five cards:");

Add a loop that executes five times with a single printf statement to print the output as shown:

System.out.println(“Deal five cards:“);

Review of Quiz 23


73


Replace the System.out.println() statement with:


Add a loop that executes five times with a single printf statement to print the output as shown:


for (int i = 1; i <= 5; i++) {

System.out.printf(" Card %d = %-17s value of card = %d.\n",

i, deck.get(i-1), value(deck.get(i-1)));}

Let’s look at this printf statement in detail

Review of Quiz 23


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for (int i = 1; i <= 5; i++) {



Let’s look at this printf statement in detail

import java.util.*;



String[] ranks = {"2", "3", "4", "5", "6", "7", "8", "9", "10", "Jack", "Queen", "King", "Ace"};

String[] suits = {"Clubs", "Diamonds", "Hearts", "Spades"};

List<String> deck = new ArrayList<String>();

for (String rank : ranks) { // build sorted deck

for (String suit : suits) {

deck.add(rank + " of " + suit);}}

Collections.shuffle(deck);


for (int i = 1; i <= 5; i++) {

System.out.printf(" Card %d = %-17s value of card = %d.\n", i, deck.get(i-1), value(deck.get(i-1)));}

}

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for (int i = 1; i <= 5; i++) {



import java.util.*;











for (int i = 1; i <= 5; i++) {


}

The %d formats an integer card numberThe %-17s left justifies (-) the String representing the card drawn in 17 character spaces.

Queen of Diamonds is largest and takes 17 characters

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for (int i = 1; i <= 5; i++) {



import java.util.*;











for (int i = 1; i <= 5; i++) {


}

Finally, we print out the value of the card in integer (%d) format

This uses the method “value” that we must write to return the value of the card

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for (int i = 1; i <= 5; i++) {



import java.util.*;











for (int i = 1; i <= 5; i++) {


}

Finally, we print out the value of the card in integer (%d) format

This uses the method “value” that we must write to return the value of the card

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for (int i = 1; i <= 5; i++) {



import java.util.*;











for (int i = 1; i <= 5; i++) {


}

public static int value(String card) {

char number = card.charAt(0);

if (number == '1') {return 10;}

if (number == 'J') {return 10;}

if (number == 'Q') {return 10;}

if (number == 'K') {return 10;}

if (number == 'A') {return 11;}

return Character.getNumericValue(number);}

Grab the first character of the card description

The first character is a 1, J, Q, or K for 10, Jack, Queen or King –each of which has value 10.

The Ace has a value of 11

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for (int i = 1; i <= 5; i++) {



import java.util.*;











for (int i = 1; i <= 5; i++) {


}









All other cards start with the value of the card

Use the methodCharacter.getNumericValue()

to convert the character to its integer value equivalent

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for (int i = 1; i <= 5; i++) {



import java.util.*;











for (int i = 1; i <= 5; i++) {


}









Here is the entire program:

import java.util.*;



String[] ranks = {"2", "3", "4", "5", "6", "7", "8", "9", "10", "Jack", "Queen", "King",

"Ace"};








for (int i = 1; i <= 5; i++) {

System.out.printf(" Card %d = %-17s value of card = %d.\n", i, deck.get(i-1),

value(deck.get(i-1)));}

}









}

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You need to download the GRE vocabulary file from the class web page

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The file will be used in Lab 13 –download by clicking here

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Different browsers have different ways of selecting the data. For most browsers, ctrl-a, will select all the data

If this does not work, highlight the first word and then do a shift-left-click on the last word

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Different browsers have different ways of selecting the data. For most browsers, ctrl-a, will select all the data

If this does not work, highlight the first word and then do a shift-left-click on the last word

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After highlighting the text, a right-click on any highlighted word will bring up the copy menu

Copy the data to the clip board

Then paste into notepad or Word and save as a text file (wordLink.txt) in the same directory as your Java programs

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After highlighting the text, a right-click on any highlighted word will bring up the copy menu

Copy the data to the clip board

Then paste into notepad or Word and save as a text file (wordLink.txt) in the same directory as your Java programs

Be sure to save the file as wordList.txt in the same directory as your Java files

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Next copy and paste the main program into DrJava

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import java.io.*; // for File (FILE from Quiz 17)




File f = new File("wordList.txt");





System.out.println("getAbsolutePath returns " + f.getAbsolutePath());

int count = 0;


input.next();

count++; }


The beginning of this file is from Quiz 17

It checks to be sure the file exists, can be read, finds its length and absolute path and finally counts the number of words in the file

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int count = 0;


input.next();

count++; }




The next part of the file sets up the text file to be read and calls the two methods that we are to write to do the Sequential Search and the Binary Search

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int count = 0;


input.next();

count++; }





File wordList = new File("wordList.txt");

String words[] = new String[count];

Scanner wordFile = new Scanner(wordList);

for (int i = 0; i < count; i++) {words[i] = wordFile.nextLine();}


System.out.print("Enter a word to search for: ");

String target = console.nextLine();

target = target.toLowerCase();

int indexSequential[] = new int[2];

indexSequential = indexOf(words, target);

int indexBinary[] = new int[2];

indexBinary = binarySearch(words, target);

Name the file wordList and set up Scanner wordFile to read the words from “wordList.txt”Set up the String array word[] to hold the count = 69,900 words in wordList.txt

Read the words from the file to the array word[]

Get the target word from the console and store it in String target

to store the results of the Sequential and Binary Searches Create 2-dimensional arrays

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public static void main(String[] args) thr ows FileNotFoundException {







int count = 0;


input.next();

count++; }





















The final part of the main program checks to see if the target was found. The print statements are different for target found and target not found

if(indexBinary[0] >= 0) {

System.out.printf("\nUsing Sequential Search, target %s found at %d in %d iterations.\n"

, target, indexSequential[0], indexSequential[1]);

System.out.printf("Using Binary Search, target %s found at %d in %d iterations.\n"

, target, indexBinary[0], indexBinary[1]);}

else {

System.out.printf("\nUsing Sequential Search, target %s was NOT found in %d iterations.\n"

, target, indexSequential[1]);

System.out.printf("Using Binary Search, target %s was NOT found in %d iterations.\n"

, target, indexBinary[1]);}

}

Printed when target is NOT found

Printed when target is found

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public static void main(String[] args) thr ows FileNotFoundException {







int count = 0;


input.next();

count++; }





















The final part of the main program checks to see if the target was found. The print statements are different for target found and target not found


System.out.printf("\nUsing Sequential Search, target %s found at %d in %d iterations.\n"


System.out.printf("Using Binary Search, target %s found at %d in %d iterations.\n"


else {

System.out.printf("\nUsing Sequential Search, target %s was NOT found in %d iterations.\n"


System.out.printf("Using Binary Search, target %s was NOT found in %d iterations.\n"


}

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Next we need to write the two search methods: Sequential Search and Binary Search

These need to be changed to Strings

These need to be changed to an integer array of size 2:int[] temp = new int[2];

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// Sequential Search p. 846 of text

public static int[] indexOf(String[] strings,

String target) {

int[] temp = new int[2];

int iterations = 0;

for (int i = 0; i < strings.length; i++) {

iterations++;

if (strings[i].equals(target)) {

temp[0] = i;

temp[1] = iterations;

return temp;}} // found it!

temp[0] = -1;


return temp; // not found

}

Strings

Change the return to an integer array size 2

Sequential Algorithm

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String target) {


int iterations = 0;


iterations++;


temp[0] = i;



temp[0] = -1;



}

Keep track of iterations

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Change the return to an integer array of size 2

We need to add code to keep track of the number of iterations

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public static int[] binarySearch(String[] strings, String target) {


int iterations = 0;

int min = 0;

int max = strings.length - 1;

while (min <= max) {

iterations++;

int mid = (max + min) / 2;

int compare = strings[mid].compareTo(target);

if (compare == 0) {

temp[0] = mid;


return temp;} // found it!

else if (compare < 0) {

min = mid + 1;} // too small

else { // compare > 0

max = mid - 1;} // too large

}

temp[0] = -1;



}

Change the return to an array of size 2

Count the iterations

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int iterations = 0;

int min = 0;



iterations++;



if (compare == 0) {

temp[0] = mid;







}

temp[0] = -1;



}

Change the return to an array of size 2

Count the iterations


100

For lapin the Binary Search take only ONE iteration

For Yoga the Binary Search has fewer iterations

For Michael the Binary Search has fewer iterations

For aback the Sequential Search has fewer iterations


101











First third of the main program


102

int count = 0;


input.next();

count++; }














Second third of the main program


103


System.out.printf("\nUsing Sequential Search, target %s found at %d in

%d iterations.\n"


System.out.printf("Using Binary Search, target %s found at %d in %d

iterations.\n"


else {

System.out.printf("\nUsing Sequential Search, target %s was NOT found

in %d iterations.\n"


System.out.printf("Using Binary Search, target %s was NOT found in %d

iterations.\n"


}

Last third of the main program


104



String target) {


int iterations = 0;


iterations++;


temp[0] = i;



temp[0] = -1;



}

Sequential Search Method


105



int iterations = 0;

int min = 0;



iterations++;



if (compare == 0) {

temp[0] = mid;







}

temp[0] = -1;



}

}

Binary Search Method

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You are to write method recursive to print words from the file wordList.txt in forward and then reverse order

You will be using the file wordList.txt from the web page

The main program has been written for you

• Sets up text file• Asks user how many

iterations• Calls recursive

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We need to write the method recursive

The recursive base (n <= 0) will print out “Reverse:”

On the way up, the method prints the words from wordList.txt in reverse order

On the way down, the method prints the words from wordList.txt in forward order

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We need to write the method recursive

The recursive base (n <= 0) will print out “Reverse:”

On the way up, the method prints the words from wordList.txt in reverse order

On the way down, the method prints the words from wordList.txt in forward order

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public static void recursive(Scanner input, int n) {

if (n <= 0) {System.out.printf("\n\nReverse:\n");}

else {


System.out.printf("\n%s ", temp);

recursive(input, n-1);

System.out.printf("\n%s ", temp);}

}

The base (n <= 0) prints out “Reverse:”

On the way down, read the next word from wordList.txt and print it out (forward order)

On the way up, just print the word out (reverse order)

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else {





}



On the way down, read the next word from wordList.txt and print it out (forward order)On the way down, read

the next word from wordList.txt and print it out (forward order)



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else {





}



On the way down, read the next word from wordList.txt and print it out (forward order)

import java.util.*;

import java.io.*;


public static void main(String[] args) throws

FileNotFoundException {




System.out.print("Enter number of recursions: ");

int n = console.nextInt();

recursive(input, n);


}



else {





}

}

Assignments for this week1. Laboratory for Chapter 12 due Today (Monday 12/1)

• IMPORTANT: When you email me your laboratory Word Document, be sure it is all in one file

2. All lab regrades must be submitted no later than midnight Monday 12/15/2014.

3. FINAL EXAM in this room, next Wednesday (12/17/2014)

4. Be sure to complete Quiz 26 before leaving class tonight• This is another program to write• You must demonstrate the program to me before you leave lab


112

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