C program to SWAP two numbers without using temporary variable | Swapping of two numbers using bit-wise operator with XOR operator | Understanding of XOR operator
/********* PROGRAM **********/
#include<stdio.h>
main()
{
int a,b;
printf(“Enter a,b values : “);
scanf(“%d%d”,&a,&b);
printf(“Before swapping a = %d t b= %d n”,a,b);
a^=b^=a^=b; //actual operation if you don’t understand, see below explanation
printf(“Before swapping a = %d t b= %d n”,a,b);
}
/********** OUTPUT ***************/
Explanation :
a^=b^=a^=b is equal to
a = a^b;
b = b^a;
a = a^b;
Here ^ is bit-wise XOR operator
Let’s take one example to illustrate this logic. before going to example just have a look on bit-wise XOR truth table
|
bit a
|
bit b
|
a ^ b (a XOR b)
|
|
0
|
0
|
0
|
|
0
|
1
|
1
|
|
1
|
0
|
1
|
|
1
|
1
|
0
|
Let us assume two values a and b.
a=11, b=22;
a=a^b; (first operation)
00001011 (Binary Equivalent of 11)
00010110 (Binary Equivalent of 22)
———
00011101 (Result is stored in a now )
——–
b = b^a;
00010110
00011101
——–
00001011 (b value )
——–
a = a^b;
00011101
00001011
——–
00010110 (a value )
——–
Now a and b are swapped
a= 22 and b = 11..
For other Swapping Techniques CLICK HERE
