swap.cpp

// C Program to swap bits  
// in a given number 
#include<stdio.h> 
  
int swapBits(unsigned int x, unsigned int p1, unsigned int p2, unsigned int n) 
{ 
    /* Move all bits of first set to rightmost side */
    unsigned int set1 =  (x >> p1) & ((1U << n) - 1); 
  
    /* Move all bits of second set to rightmost side */
    unsigned int set2 =  (x >> p2) & ((1U << n) - 1); 
  
    /* XOR the two sets */
    unsigned int xo = (set1 ^ set2); 
  
    /* Put the xor bits back to their original positions */
    xo = (xo << p1) | (xo << p2); 
  
    /* XOR the 'xor' with the original number so that the  
       two sets are swapped */
    unsigned int result = x ^ xo; 
  
    return result; 
} 
  
/* Driver program to test above function*/
int main() 
{ 
    int res =  swapBits(28, 0, 3, 2); 
    printf("\nResult = %d ", res); 
    return 0; 
}