C语言实现字符串子串统计

#include <stdio.h>

int main() { char str[100001]; scanf('%s', str);

int count = 0;
int i = 0;
while (str[i] != '\0') {
    if (str[i] == '1') {
        count++;
    }
    i++;
}

int answer = count * (count + 1) / 2;
printf('%d\n', answer);

return 0;

}