120. 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
    if (num == 0) {
        printf("0");
        return;
    }

    char digits[] = "0123456789ABCDEF";
    char res[5];

    int i = 0;
    while (num > 0){
        res[i] = digits[num % 16];
        num = 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;
}