二分查找32位整数的前导0个数

参考自Matrix67！

//二分查找32位整数的前导0个数
//二分查找思想
#include <stdio.h>

int main() {
    unsigned int n;
    while (scanf("%u", &n) != EOF) {
        if (n == 0) printf ("32\n");
        else {
            int s = 1;
            if ((n >> 16) == 0) {s += 16; n <<= 16;}
            if ((n >> 24) == 0) {s += 8;  n <<= 8;}
            if ((n >> 28) == 0) {s += 4;  n <<= 4;}
            if ((n >> 30) == 0) {s += 2;  n <<= 2;}
            s -= (n >> 31);
            printf ("%d\n", s);
        }
    }
    return 0;
}