Convert Decimal Number to Binary or Hex Without itoa function

Code

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

void print_base(uint16_t num, uint8_t base) {
    if (num == 0){
        printf("0");
        return;
    }

    char digits[17] = "0123456789ABCDEF";
    char str[16];
    int i = 0;
  
    while (num > 0){
        str[i++] = digits[num % base];
        num /= base;
    }

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

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

    print_base(num, base);
    return 0;
}

Solving Approach