program to swap two numbers

1// Method 1: With temporary variable
2temp = A
3A = B
4B = temp
5// without temporary variable
6// Method 2: Addition and subtraction
7A = A + B
8B = A - B
9A = A - B
10// Method 3: Muitply and Divide
11A = A * B
12B = A / B
13A = A / B

1
2#include<stdio.h>  
3 int main()    
4{    
5int a=10, b=20;      
6printf("Before swap a=%d b=%d",a,b);      
7a=a+b;//a=30 (10+20)    
8b=a-b;//b=10 (30-20)    
9a=a-b;//a=20 (30-10)    
10printf("\nAfter swap a=%d b=%d",a,b);    
11return 0;  
12}   
13

1#include <stdio.h>
2#include <stdlib.h>
3
4int main()
5{
6  	//initialize variables
7	int num1 = 10;
8	int num2 = 9;
9  	int tmp;
10  	
11  	//create the variables needed to store the address of the variables
12  	//that we want to swap values
13  	int *p_num1 = &num1;
14  	int *p_num2 = &num2;
15  
16  	//print what the values are before the swap
17  	printf("num1: %i\n", num1);
18    printf("num2: %i\n", num2);
19  
20  	//store one of the variables in tmp so we can access it later
21  	//gives the value we stored in another variable the new value
22  	//give the other variable the value of tmp
23  	tmp = num1;
24  	*p_num1 = num2;
25  	*p_num2 = tmp;
26
27  	//print the values after swap has occured
28   	printf("num1: %i\n", num1);
29    printf("num2: %i\n", num2);
30  	
31	return 0;
32}
33

1#include<stdio.h>
2
3int main()
4{
5    int x = 20, y = 30, temp;
6    
7    temp = x;
8    x = y;
9    y = temp;
10    
11    printf("X = %d and Y = %d", x, y);
12    
13    return 0;
14}