Convert Hexadecimal String to Integer Without strtol or sscanf functions

Code

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

uint16_t hex_to_uint(const char *str) {
    // Your logic here
    int val = 0;
    for (int i = 0; str[i] != '\0'; i++) {
        if(str[i] >= 'A' && str[i] <= 'Z' || str[i] >= '0' && str[i] <= '9') {
            int digit = (str[i] >= 'A') ? (str[i] - 'A' + 10) : (str[i] - '0');
            val = (val << 4) | digit;
        }
        else {
            int digit = (str[i] >= 'a') ? (str[i] - 'a' + 10) : (str[i] - '0');
            val = (val << 4) | digit;
        }
    }
    return val;
}

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

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

Solving Approach