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
    char buffer[17];
    int idx = 0;

    if(num == 0){
        printf("0");
        return;
    }
    while(num > 0){
        uint8_t digit = num % base;
        if(digit < 10){
            buffer[idx] = '0' + digit;
            idx++;
        }
        else{
            buffer[idx] = 'A' + (digit - 10);
            idx++;
        }
        num /= base;
    }
    for(int i = idx - 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;
}