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 i = 0;
    uint16_t result = 0;
    while (str[i] != '\0')
    {
        int res =  str[i] - '0';
        result <<= 1;
        if ( res == 1)
        {            
            result |= 1 ;
        }
        i++;
    }
    return result;
}
int main() {
    char bin[20];
    scanf("%s", bin);
    printf("%u", binary_to_uint(bin));
    return 0;
}

Solving Approach