Convert Integer to Hex String Without sprintf or itoa functions

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

void print_hex(uint16_t num) {
    // Your logic here
    char arr[20];
    int i = 0;

    if(num == 0)
    {
        printf("0");
        return;
    }

    while(num > 0)
    {
        uint8_t rem = num % 16;

        if(rem < 10)
            arr[i] = rem + '0';
        else
            arr[i] = rem - 10 + 'A';

        num /= 16;
        i++;
    }

    for(int j = i - 1; j >= 0; j--)
        printf("%c", arr[j]);
}

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