Array quadruplet - being interviewer

ArrayQuadruplet_beingInterviewer.java

import java.io.*;
import java.util.*;

class Solution {
  
  static int[] findArrayQuadruplet(int[] arr, int s) {
    // your code goes here
    // 1. Scan through arr
    // 2.     scan through next 3 numbers
    // 3.       if sum == s, we now all the four numbers, we return then
    for (int i=0; i<arr.length;i++) {
      
      // What is the condition I stop?? - to decide
      for (int j=i+1;; j++) {  // first< second< third < fourth, 1, 2, 3,4
        
        // we have overflow over here.
        // e.g 2,7,4,0,9
        //     0 1 2 3 4; i+1 % 3 
        int        
        int sum = arr[i] + arr[i+1%arr.length] + arr[i+2] + arr[i+3];
        
      }   
       
    }
    // Leetcode
    //  Two sum algorithm - two pointer technique 
    // 1,  2,  3 4 5 6 7 8 9, 10, given two sum  = 12
    // |                       |
    // 1 + 10 = 11 < 12 -> move smalle value forward
    //     |                   |  -> 2 + 10 = 12 
    // time complexity -> 
    
    Array.Sort(arr); 
    
    // 1, 2, 3, 4, 5 -> all possible - 5 out of 4, 5 choices 
    int length = arr.length; 
    for(int first = 0; first < length - 3; first++)
    {
      for(int second = first + 1; second < length - 2; second++)
      {
        for(int third = second + 1; third < length - 1; third++)
        {
          for(int fourth = third + 1; fourth < length; fourth++)
          {
            int sum = arr[first] + arr[second] + arr[third] + arr[fourth]; 
            if(sum == s)
            {
              return new int[]{}
            }
          }
        }
      }
    }
    
  
    int []res = {0,4,7,9};
    return res;
  }

  public static void main(String[] args) {
    myTest();
  }
  
  static void myTest () { 
    int []arr = {2, 7, 4, 0, 9, 5, 1, 3};
    int s = 20;
    
    int []expected = {0,4,7,9};
    
    int []output = findArrayQuadruplet(arr, s); 
    
    for (int i =0; i<4; i++) {
      if (output[i] != expected[i]) 
        System.out.println ("fail");
    }
    System.out.println ("Success");
  
  }

}