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

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

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

    while(*str !=  '\0'){
        char x = *str;
        int digit = 0;
        if(x >= 'a'){
            digit = x - 'a' + 10;
        }else if(x >= 'A'){
            digit = x-'A' +10;
        }else{
            digit = x -'0';
        }
        ans = (ans<<4)|digit;
        str++;
    }

    return ans;
}

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

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