Convert Binary String to Integer Without strtol function or Libraries

Code

#include <stdio.h>
#include <stdint.h>
#include <math.h>

uint16_t binary_to_uint(const char *str) {
    uint16_t res = 0;
    for (int i = 0; str[i] != '\0'; i++) {
        res = (res << 1) | (str[i] - '0');
    }
    return res;
}

int main() {
    char bin[20];
    scanf("%s", bin);

    printf("%u", binary_to_uint(bin));
    return 0;
}

Solving Approach