Convert Hexadecimal String to Integer Without strtol or sscanf functions

Code

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

uint16_t hex_to_uint(const char *str) {
    // Your logic here
    uint16_t val = 0;
    while(*str) {
        val = val * 16 + (toupper(*str) >= 'A' ? (10 + (toupper(*str) - 'A')) : (*str - '0'));
        str++;
    }
    return val;
}

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

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

Solving Approach