Convert Integer to Hex String Without sprintf or itoa functions

Code

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

void print_hex(uint16_t num) {
    if (num == 0) 
    {
        putchar('0');
        return;
    }
    char hex_conv[] = "0123456789ABCDEF";
    char res[5]; 
    int i = 0; 
    while (num)
    {
        res[i] = hex_conv[num % 16]; 
        num /= 16; 
        i++; 
    }

    for (int j = i - 1; j >= 0; j--)
    {
        putchar(res[j]);
    }
}

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

Solving Approach