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
    uint16_t value = 0;
    while(*str != '\0'){
        value *= 16;
        if(*str >= '0' && *str <= '9'){
            value += *str - '0';
        }
        else if (*str >= 'A' && *str <= 'F'){
            value += *str - 'A' + 10;
        }
         else if (*str >= 'a' && *str <= 'f'){
            value += *str - 'a' + 10;
        }
        str++;
    }
    return value;
}

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

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

Solving Approach