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

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

void print_hex(uint16_t num) {
    char hex[17]="0123456789ABCDEF";
    char result[5] = "0000";
    int idx = 3; 
    if(num==0) {
        putchar('0');
        return;
        }
    while(num>0){
        result[idx]=hex[num%16];
        num/=16;
        idx--;
    }
    printf("%s",result+(idx+1));
}

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