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) {
    int value=0;
    for(int i=0;i<str[i];i++){
        char c=str[i];
        if(c>=97){c=c-32;}//converted to uppercase
        int digit =(c>='A')?(c-'A'+10):(c-'0');
        value=(value<<4)|digit; 
    }
    return value;
}

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

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

Solving Approach