Count Set Bits in an Integer

Approach & Code

#include <stdio.h>
#include <stdint.h>

/*
Count set bits
countSetBits ->api which takes in a positive integer (assumption)

Input: 5 (0101)
Output: 2 

Plan:
- Keep shifting to the right and & with 1U (do this a while loop)
- increment a count var if 1 is encountered
- return the count

Edge cases
- can the number be negative
- what happens when 0 is entered
- uint32 is the upper limit


*/

int countSetBits(unsigned int n) {
    // Write your code here
    if(n == 0) return 0;

    uint8_t countOnes = 0;

    while(n)
    {
        if(n & 1U != 0) countOnes++;
        n = n >> 1U;
    }

    return countOnes;
}

int main() {
    int n;
    scanf("%d", &n);
    printf("%d", countSetBits(n));
    return 0;
}

Solving Approach