Count Set Bits in an Integer

#include <stdio.h>

int countSetBits(unsigned int n) {
    int count = 0;
    for (size_t i = 0; i < sizeof(n)*8; i++){
        if ((n>>i) & 1) {
            count++;
        }
    }
    return count;
}

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