30. Count Set Bits in an Integer

#include <stdio.h>

int countSetBits(unsigned int n) {
    int count = 0;
    while (n > 0) {
        count += (n & 1);  // Check last bit
        n = n >> 1;        // Shift right
    }
    return count;
}

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