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;
    int digit;

    for(int i=0;str[i];i++){
        char c=str[i];
        if (c >= '0' && c <= '9') {
            digit = c - '0';
        } else if (c >= 'A' && c <= 'F') {
            digit = c - 'A' + 10;
        } else if (c >= 'a' && c <= 'f') {
            digit = c - 'a' + 10;
        } else { 
            break; 
        }
        val = (val << 4) | digit;
    }
    return val;
}

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

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

Solving Approach