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 str[16];
    uint8_t value;
    str[16] = '\0';
    int i = 15;
    while (num > 0) {
        value = (uint8_t)(num % base);
        num = num / base;
        if (value < 10) {
            str[i--] = '0' + value;
        } else {
            str[i--] = 'A' + value - 10;
        }
    }

    printf("%s", str + i + 1);
}

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

    print_base(num, base);
    return 0;
}

Solving Approach