Create Path Sum Root to Leaf

Author: akshayavb99

Course 2 - Data Structures in JAVA/Lecture 12 - Binary Trees - II/Path Sum Root to Leaf

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+/*
+For a given Binary Tree of type integer and a number K, print out all root-to-leaf paths where the sum of all the node data along the path is equal to K.
+
+Input Format:
+The first line of input will contain the node data, all separated by a single space. Since -1 is used as an indication whether the left or right node data exist for root, it will not be a part of the node data.
+The second line of input contains an integer value K.
+
+Output Format:
+Lines equal to the total number of paths will be printed. All the node data in every path will be printed in a linear fashion taken in the order they appear from top to down bottom in the tree. A single space will separate them all.
+
+Constriants:
+1 <= N <= 10^5
+0 <= K <= 10^8
+Where N is the total number of nodes in the binary tree.
+Time Limit: 1 second
+
+Sample Input 1:
+2 3 9 4 8 -1 2 4 -1 -1 -1 6 -1 -1 -1 -1 -1
+13
+Sample Output 1:
+2 3 4 4 
+2 3 8
+
+Sample Input 2:
+5 6 7 2 3 -1 1 -1 -1 -1 9 -1 -1 -1 -1
+13
+Sample Output 2:
+5 6 2
+5 7 1
+*/
+
+import java.util.*;
+/*
+	
+	Following is the structure used to represent the Binary Tree Node
+
+	class BinaryTreeNode<T> {
+		T data;
+		BinaryTreeNode<T> left;
+		BinaryTreeNode<T> right;
+
+		public BinaryTreeNode(T data) {
+			this.data = data;
+			this.left = null;
+			this.right = null;
+		}
+	}
+
+*/
+
+public class Solution {
+
+	public static void rootToLeafPathsSumToK(BinaryTreeNode<Integer> root, int k) {
+		//Your code goes here
+        String arr="";
+        rootToLeafPathsSumToK(root,k,arr);
+	}
+    
+    public static void rootToLeafPathsSumToK(BinaryTreeNode<Integer> root, int k,String arr)
+    {
+        if (root==null)
+        {
+            return;
+        }
+        
+        int rootData=root.data;
+        //System.out.println("Root data: "+rootData);
+        //System.out.println("k: "+k);
+        //System.out.println("Old Arraylist: "+arr);
+        arr=arr+rootData+" ";
+        if(k==rootData && root.left==null && root.right==null)
+        {
+            //System.out.print("Path found: ");
+            //for (int i=0;i<arr.length();i++)
+               //System.out.print(arr.charAt(i)+" ");
+            //System.out.println();
+            System.out.println(arr);
+            return;
+        }
+        //System.out.println();
+        
+        rootToLeafPathsSumToK(root.left,k-rootData,arr);
+        rootToLeafPathsSumToK(root.right,k-rootData,arr);
+    }
+
+}