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Count number of bits to be flipped to convert A to B

YasminRadwan26
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2022-06-25
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Count number of bits to be flipped to convert A to B

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YasminRadwan26
2022-06-25
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In this question, you need to count flipped bits that require to convert A to B. To accomplish this task you need to find the number of bits that are different in A and B.

Suppose, A = 8, B = 7
Binary representation of A => 00001000
Binary representation of B => 00000111
Here we have to flip highlighted four bits of A
to make it B.

Algorithm

  1. Calculate XOR of A and B.With the help of XOR, we will discard the common bits and set the bits that are different in numbers A and B.
  2. Count the set bits of the above calculated XOR result.

Example code,

#include <stdio.h>
//function to calculate flipped bits
int CountFlippedBits(int A, int B)
{
    int XorResult = 0;
    int count = 0;
    //Doing Ex-or
    XorResult = (A ^ B);
    //Count set bits
    while (XorResult)
    {
        count += XorResult & 1;
        XorResult >>= 1;
    }
    return count;
}
int main()
{
    int A = 8;
    int B = 7;
    int ret = 0;
    //Function return count of flipped bits
    ret = CountFlippedBits(A,B);
    printf("Flipped Bits = %d\n",ret);
    return 0;
}

Output: Flipped Bits = 4

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