Swap Two Numbers using third variable & without using third variable

Write a function that swaps the values of the two variables using third variable called as temporary variable.




For example: 
If A=5 and B=6 , after swapping the variables should have values as A=6 and B=5.

Method 1:

1. Copy the value of A to the temporary variable, say temp. Now, A=5, B=6, temp=5
2. Copy the value of B to A. A=6, B=6, temp=5
3. Copy the value of temp to B. A=6, B=5, temp=5
4. Now the variables A & B has the swapped values.

Implementation:


#include<stdio.h> int main() { int var1,var2,temp; printf("Enter value 1:\n"); scanf("%d",&var1); printf("Enter value 2:\n"); scanf("%d",&var2); printf("Before Swapping:\nValue1=%d\tValue2=%d\n",var1,var2); temp=var1; var1=var2; var2=temp; printf("After Swapping:\nValue1=%d\tValue2=%d",var1,var2); return 0; }

Output:

Enter value 1: 5
Enter value 2: 6

Before Swapping:
Value1=5     Value2=6

After Swapping:
Value1=6     Value2=5

Method 2:

Swapping the values of two variables can be done, without using a third variable also, using the following method.

a=a+b;
b=a-b;
a=a-b; 

Where a and b are the two numbers whose values should be swapped(Exchanged) between each other. 

Implementation:
#include<stdio.h> #include<conio.h> int main() { int a,b; printf("Enter the value of a:"); scanf("%d",&a); printf("Enter the value of b:"); scanf("%d",&b); printf("Before swapping:\na=%d\tb=%d",a,b); a=a+b; b=a-b; a=a-b; printf("\nAfter swapping:\na=%d\tb=%d",a,b); return 0; }


Output:

Enter the value of a: 5
Enter the value of b: 6
Before swapping:
a=5       b=6
After swapping:
a=6       b=5