Convert Binary String to Integer Without strtol function or Libraries

Code

#include <stdio.h>
#include <stdint.h>
#include <string.h>
uint16_t binary_to_uint(const char *str) {
    int len = strlen(str);
    int p = 1,res = 0;
    for(int i=len-1;i>=0;i--){
        if(str[i]=='1'){
            res+=p;
        }
        p*=2;
    }
    return res;
}
int main() {
    char bin[20];
    scanf("%s", bin);

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

Solving Approach