函式_How Many Ones Needed?

int count_ones(int dec_num);


int count_ones(int dec_num) {
    int count = 0;
    while (dec_num > 0) {
        if (dec_num % 2 == 1) {
            count++;
        }
        dec_num = dec_num / 2;
    }
    return count;
}

#include <stdio.h>


int main() {
    int a, b;

    while (scanf("%d%d", &a, &b)) {
        int total_ones_num = 0;
        if (a == 0 && b == 0) break;
        for (int i = a; i <= b; i++) {
            total_ones_num += count_ones(i);
        }
        printf("%d\n", total_ones_num);
    }

    return 0;
}