120. 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 digits[17] = "0123456789ABCDEF";
    char buffer[20]; // Enough to hold result
    int i = 0;

    while (num > 0) {
        buffer[i++] = digits[num % 16];
        num /= 16;
    }

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

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