Convert Binary String to Integer Without strtol function or Libraries

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

uint16_t binary_to_uint(const char *str) {
    // Your logic here
    uint16_t result=0;
    int len = strlen(str);
    for(int i=0;i<len;i++)
    {
        if(str[len -1-i] == '1')
        {
            result += (1 << i);
        }
    }
    return result;
}

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

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