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Author: shatakshigarg

PAIR SUM IN A BST.txt

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+import java.util.*;
+public class Solution {
+	/*
+	 * BinaryTreeNode class
+	 * 
+	 * class BinaryTreeNode<T> 
+	 * { 
+	 * 		T data; 
+	 * 		BinaryTreeNode<T> left; 
+	 * 		BinaryTreeNode<T> right;
+	 *		public BinaryTreeNode(T data) 
+	 *		{
+	 *  		this.data = data; 
+	 *  	} 
+	 *  }
+	 */
+	
+	public static void printNodesSumToS(BinaryTreeNode<Integer> root, int s) {
+		// Write your code here
+        if (root==null)
+            return;
+        else
+        {
+            ArrayList<Integer> arr = convertToArray(root);
+        	Collections.sort(arr);
+            //for (int i=0;i<arr.size();i++)
+            //{
+            //    System.out.print (arr.get(i)+" ");
+            //}
+            //System.out.println();
+        	printPairSum(arr,s);
+        }
+        
+	}
+    
+    private static ArrayList<Integer> convertToArray(BinaryTreeNode<Integer> root)
+    {
+        if (root==null)
+        {
+            ArrayList<Integer> arr = new ArrayList<Integer>();
+            return arr;
+        }
+        
+        
+        ArrayList<Integer> currArr = new ArrayList<Integer>();
+        ArrayList<Integer> leftArr = convertToArray(root.left);
+        if (!leftArr.isEmpty())
+        {
+            currArr.addAll(leftArr);
+        }
+        
+        currArr.add(root.data);
+        
+        ArrayList<Integer> rightArr = convertToArray(root.right);
+        if (!rightArr.isEmpty())
+        {
+            currArr.addAll(rightArr);
+        }
+        return currArr;
+    }
+    
+    private static void printPairSum(ArrayList<Integer> arr, int s)
+    {
+        int i=0,j=arr.size()-1;
+        while(i<j)
+        {
+            int val1=arr.get(i);
+            int val2=arr.get(j);
+            if (val1+val2>s)
+            {
+                j=j-1;
+            }
+            else if(val1+val2<s)
+            {
+                i=i+1;
+            }
+            else
+            {
+                System.out.println(val1+" "+val2);
+                i=i+1;
+                j=j-1;
+            }
+                
+        }
+    }
+}