120. Convert Integer to Hex String Without sprintf or itoa functions

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

const char hex_digits[] = "0123456789ABCDEF";

void print_hex(uint16_t num) {
    // Your logic here
    char res[16];
    int i = 0;
    do {
        res[i++] = hex_digits[num % 16];
        num = num >> 4;
    } while (num);
    while (i--) printf("%c", res[i]);
}   

int main() {
    uint16_t num;
    scanf("%hu", &num);
    print_hex(num);
    return 0;
}