Convert Integer to Hex String Without sprintf or itoa functions

Code

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

void print_hex(uint16_t num) {
    // Your logic here
    char arr[32];
    int index=0;
    if(num==0){
        printf("%d",0);
        return;
    }
    while(num>0){
        int n=num%16;
        // printf("%X\n",n);
        arr[index++]=n;
        num=num/16;
    }
    for(int i=index-1;i>=0;i--){
        printf("%X",arr[i]);
    }
}

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

Solving Approach