Convert Integer to Hex String Without sprintf or itoa functions

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

void print_hex(uint16_t num) {
    
    if (num == 0) {
        printf("0");
        return;
    }

    char map[] = "0123456789ABCDEF";
    int buffer[4];

    int i = 0;

    while (num) {
        buffer[i++] = map[num % 16];
        num /= 16;
    }

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

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