Convert Decimal Number to Binary or Hex Without itoa function

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

void print_base(uint16_t num, uint8_t base) {
    // Your logic here
    if (num == 0) {
        printf("0");
        return;
    }
    char buffer[17];
    int index = 0;

    while (num > 0) {
        int remainder = num % base;
        
        if (remainder < 10) {
            buffer[index] = '0' + remainder;  
        } else {
            buffer[index] = 'A' + (remainder - 10);
        }
        
        num = num / base;
        index++;
    }
    for (int i = index - 1; i >= 0; i--) {
        printf("%c", buffer[i]);
    }
}

int main() {
    uint16_t num;
    uint8_t base;
    scanf("%hu %hhu", &num, &base);

    print_base(num, base);
    return 0;
}