Convert Binary String to Integer Without strtol function or Libraries

Code

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


uint16_t binary_to_uint(const char *str) {
    // Your logic here
    const char *start = str;
    uint16_t val=0;
    int power = 0;
    while(*str != '\0'){
        str++;
    }
    str--;
    while(str >= start){
        if(*str == '1'){
            val += pow(2,power);
        }
        str--;
        power++;


    }
    
    return val;
}

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

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

Solving Approach