Convert Binary String to Integer Without strtol function or Libraries

Code

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

uint16_t binary_to_uint(const char *str) {
    int result = 0;
    for(int i = 0; str[i]; i++)
    {
        result <<=1;
        if(str[i] == '1') result |= 1;
        else if(str[i] != '0') return 0xFFFF;
    }
    return result;

}

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

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

Solving Approach