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Tutorial 9 String and StructureNUS SCHOOL OF COMPUTING

CS1010E PROGRAMMING METHODOLOGY

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Quick Summary1. Structure introduces the concept of an Object. The Object can

contain many attributes. (Person: Gender, Age, etc.)1. Two ways to declare a structure:

typedef struct{…}[identifier];struct [identifier]{…};

2. To retrieve the attributes of a structure use “.” operator:Person.Gender = “male”;Person.Age = 20;

3. For Structures with pointers:Person->Gender = “male”;Person->Age = 20;

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Q1: Self Implementation of <string.h>

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Q1: Self Implementation of <string.h>

R A D A R \0

Left Rightstrlen = right – left;

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Q1: Self Implementation of <string.h>

R A D A R \0

s1

s2

t

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Q1: Self Implementation of <string.h>

R A D A R \0

R A \0

s1

s2

t

my_strcpy(s1,s2);

R A R A D A R \0

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Q1: Self Implementation of <string.h>

R A D A R \0

R A D A R \0

s1

s2

Loop until (s1 becomes \0) or (a difference is found):

Return the difference

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Q2: Christmas Carol

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Q2: Christmas Carol

On any particular day:

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Constant strings:

“On the ”

“day of Christmas,\n”

“my true…\n”

“and ”

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Q2: Christmas Carol

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Q2: Christmas Carol

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Q2: Christmas Carol

Because a word ends with either of the following:Space, Comma, Fullstop.

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Q2: Christmas Carol

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Q3: Overlapping Rectangles

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Q3: Overlapping Rectangles

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Q3: Overlapping Rectangles

If the points do not fulfil the pre-condition required, we just need to swap the two points.

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Q3: Overlapping Rectangles

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Q3: Overlapping Rectangles

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It is easier to check if the two rectangles do not overlap:

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Q3: Overlapping Rectangles

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Q4: Snapback Problem

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Q4: Snapback Problem

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Q4: Snapback Problem

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Q4: Snapback Problem

Bubble sort algorithm is used.This is an improved version of the bubble sort.What is the difference?

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Q4: Snapback Problem

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Q4: Snapback Problem

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Q4: Snapback Problem

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1 0 0 1 1 … 1 1 0

In the binary sequence, 1 means take the item number j, 0 means omit the item number j.

We use this binary sequence approach to enumerate all the possible ways to take the items available and compare the value.