119. Convert Hexadecimal String to Integer Without strtol or sscanf functions

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

uint8_t to_digit(char c) {
    if(c >= '0' && c <= '9') return c - '0';
    else if (c >= 'a' && c <= 'f') return c - 'a' + 10;
    else if (c >= 'A' && c <= 'F') return c - 'A' + 10;
    else return 0;
}

uint16_t hex_to_uint(const char *str) {
    // Your logic here
    uint16_t result = 0;
    int i = 0;

    while (str[i]) {
        result = (result * 16) + to_digit(str[i++]);
    }

    return result;
}

int main() {
    char hex[10];
    scanf("%s", hex);

    printf("%u", hex_to_uint(hex));
    return 0;
}