AddTwo Algorithm

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

public class OrdArray {
   private int[] a;                 // ref to array a
   private int nElems;               // number of data items
   
//-----------------------------------------------------------
   public OrdArray(int max) {          // constructor
     a = new int[max];             // create array
     nElems = 0;
   }
//-----------------------------------------------------------
   
   public int size() { 
     return nElems; 
   }
   //-----------------------------------------------------------
   
   public int find(int searchKey) {
     int lowerBound = 0;
     int upperBound = nElems-1;
     int curIn;
     
     while(true) {
       curIn = (lowerBound + upperBound ) / 2;
       if (a[curIn]==searchKey)
         return curIn;              // found it
       else if (lowerBound > upperBound)
         return nElems;             // can't find it
       else {                         // divide range
         if (a[curIn] < searchKey)
           lowerBound = curIn + 1; // it's in upper half
         else
           upperBound = curIn - 1; // it's in lower half
       }  // end else divide range
     }  // end while
   }  // end find()
   
   //-----------------------------------------------------------
   public void insert(int value) {   // put element into array
      int j;
      for (j=0; j<nElems; j++)        // find where it goes
        if (a[j] > value)            // (linear search)
        break;
      for (int k=nElems; k>j; k--)    // move bigger ones up
         a[k] = a[k-1];
      a[j] = value;                  // insert it
      nElems++;                      // increment size
   }  // end insert()
   
   //-----------------------------------------------------------
   public boolean delete(int value) {
      int j = find(value);
      if (j==nElems)                  // can't find it
         return false;
      else                           // found it
         {
         for(int k=j; k<nElems; k++) // move bigger ones down
            a[k] = a[k+1];
         nElems--;                   // decrement size
         return true;
         }
      }  // end delete()
   
   //-----------------------------------------------------------
   public void display() {             // displays array contents
      for (int j=0; j<nElems; j++)       // for each element,
        System.out.print(a[j] + " ");  // display it
      System.out.println("");
   }
   
   @Override
   public String toString() {
	   StringBuilder sb = new StringBuilder();
	   for (int i=0; i<nElems; i++){
		   sb.append(a[i]+" ");
	   }
	   return sb.toString();
   }
   //-----------------------------------------------------------
   
	public int[] merge(OrdArray arr) {
		// YOUR CODES
		OrdArray third = new OrdArray(arr.nElems+nElems);
		
		for(int i=0; i<nElems;i++) {
			third.insert(a[i]);
		}
		
		for(int i=0; i<arr.nElems;i++) {
			third.insert(arr.a[i]);
		}
		
		
		return third.a;
	}

	public int[] addTwo(int target) {
		// YOUR CODES
		int begin= 0;
		int end = nElems-1;
		int[] indexes= new int[2];
		int dummy[]= {-1,-1};
		
		while(begin<end) {
			int sum = a[begin]+a[end];
			if(sum==target) {
				indexes[0]=begin;
				indexes[1]=end;
				
				break;
			} else if( sum<target) {
				begin++;
			}
			else {
				end--;
			}
			
		}
		if(indexes[0]==0 && indexes[1]==0) {
		return dummy; 
		}
		else {
			return indexes;
		}
		
		// For compilation, you need to change it.
	}
   
   public static void main(String[] args){
     // YOUR CODES to test the merge() method.
	   
	 // The following are the codes to test the addTwo() method
	   
	 OrdArray arr  = new OrdArray(50);
	 arr.insert(12);
	 arr.insert(10);
	 arr.insert(24);
	 arr.insert(0);
	 arr.insert(6);
	 arr.insert(5);
	 arr.insert(7);
	 arr.insert(2);
	 arr.display();
	 
	 //Creating two ordered arrays
//	 int[] secondarr= {2,4,6,8,10,10};
	 
	 OrdArray firstarr = new OrdArray(50);
	 firstarr.insert(1);
	 firstarr.insert(3);
	 firstarr.insert(5);
	 firstarr.insert(5);
	 firstarr.insert(7);
	 firstarr.insert(11);
	 firstarr.insert(9);
	 
//	 firstarr.display();
	

	 OrdArray secondarr = new OrdArray(50);
	 secondarr.insert(2);
	 secondarr.insert(6);
	 secondarr.insert(8);
	 secondarr.insert(4);
	 secondarr.insert(10);
	 secondarr.insert(10);
	 
	 System.out.println(Arrays.toString(secondarr.merge(firstarr)));

//	 secondarr.display();
	 
	 
	
	
	 
	 
	
//	 arr.merge(firstarr);
	 
	 
	 Scanner console = new Scanner(System.in);
	 System.out.print("Please enter a target number: ");
	 int target = console.nextInt();
	 System.out.println("The two elements that can add up to " + target + " are at indexes: " + Arrays.toString(arr.addTwo(target)));
	 console.close();
   }
   
}  // end class OrdArray