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) {
    // Your logic here
    uint16_t res=0;
    for(int i=0;str[i];i++)
    {
        res<<=1;
        if(str[i] == '1') res |= 1;
        else if(str[i] != '0') return 0xFFFF;

    }
    return res;
}

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

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

Solving Approach