Convert Hexadecimal String to Integer Without strtol or sscanf functions

Code

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

uint8_t hex_char_to_val(char c) {
    if (c>='0'&&c<='9') return c-'0';
    else if (c>='A'&&c<='F') return c-'A'+10; 
    else if (c>='a'&&c<='f') return c-'a'+10; 
    else return 0; 
}

uint16_t hex_to_uint(const char *str) {
    // Your logic here
    uint16_t result =0; 
    for (int i=0; str[i]!='\0'; i++) {
        result<<=4; 
        result |= hex_char_to_val(str[i]);
    }
    return result;
}

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

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

Solving Approach