118. Convert Binary String to Integer Without strtol function or Libraries

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

uint16_t binary_to_uint(const char *str) {
    uint16_t num = 0U;
    const char offset = '0'; 

    // compute length of string
    int len = 0;
    while (str[len] != '\0') {
        len++;
    }

    // convert string to number
    uint16_t power = 1U; 
    for (int i = len - 1; i >= 0; i--) {
        num += (str[i] - offset) * power;
        power *= 2;
    }
    return num;
}

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

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