120. Convert Integer to Hex String Without sprintf or itoa functions

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

void print_hex(uint16_t num) {
    if(num==0) {printf("0");return; }
    int i=0,re,temp,k;
    char arr[500];
    while(num){
        re=num%16;
        if(re>9){
            arr[i]=re-10+'A';
            i++;
        }
        else{
           arr[i]=re+'0';
           i++;
        }
        num=num/16;
    }
    arr[i]='\0';
    for(k=i-1;k>=0;k--){
        printf("%c",arr[k]);
    }
}

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