path sum

Author: fishercoder1534

EASY/src/easy/PathSum.java

@@ -27,25 +27,37 @@ public boolean hasPathSum(TreeNode root, int sum) {
 
     public static void main(String...strings){
         PathSum test = new PathSum();
-//        TreeNode root = new TreeNode(1);
-//        root.left = new TreeNode(2);
-//        int sum = 1;
+        TreeNode root = new TreeNode(5);
+        root.left = new TreeNode(4);
+        int sum = 5;
 
-        TreeNode root = new TreeNode(1);
-        root.left = new TreeNode(-2);
-        root.left.left = new TreeNode(1);
-        root.left.right = new TreeNode(3);
-        root.right = new TreeNode(-3);
-        root.right.left = new TreeNode(-2);
-        root.left.left.left = new TreeNode(-1);
-        int sum = 2;
+//        TreeNode root = new TreeNode(1);
+//        root.left = new TreeNode(-2);
+//        root.left.left = new TreeNode(1);
+//        root.left.right = new TreeNode(3);
+//        root.right = new TreeNode(-3);
+//        root.right.left = new TreeNode(-2);
+//        root.left.left.left = new TreeNode(-1);
+//        int sum = 2;
 //         1
 //        / \
 //      -2   -3
 //      / \   / 
 //     1   3 -2 
 //    /      
 //   -1
-        System.out.println(test.hasPathSum(root, sum));
+//        System.out.println(test.hasPathSum(root, sum));
+        System.out.println(test.hasPathSumAgain(root, sum));
     }
+    
+
+    public boolean hasPathSumAgain(TreeNode root, int sum) {
+        if(root == null) return false;
+        if(root.left == null && root.right == null){
+            if(sum == root.val) return true;
+            else return false;
+        }
+        return hasPathSum(root.left, sum - root.val) || hasPathSum(root.right, sum - root.val);
+    }
+
 }

README.md

@@ -41,6 +41,7 @@
 |118|[Pascal's Triangle](https://leetcode.com/problems/pascals-triangle/)|[Solution](../../blob/master/EASY/src/easy/PascalsTriangle.java)| O(n^2)|O(1) | Easy| 
 |117|[Populating Next Right Pointers in Each Node II](https://leetcode.com/problems/populating-next-right-pointers-in-each-node-ii/)|[Solution](../../blob/master/HARD/src/hard/PopulatingNextRightPointersinEachNodeII.java)| O(n)|O(1) | Hard| BFS
 |116|[Populating Next Right Pointers in Each Node](https://leetcode.com/problems/populating-next-right-pointers-in-each-node/)|[Solution](../../blob/master/MEDIUM/src/medium/PopulatingNextRightPointersinEachNode.java)| O(n)|O(1) | Medium| BFS
+|112|[Path Sum](https://leetcode.com/problems/path-sum/)|[Solution](../../blob/master/EASY/src/easy/PathSum.java)| O(n)|O(1) | Easy| DFS
 |111|[Minimum Depth of Binary Tree](https://leetcode.com/problems/minimum-depth-of-binary-tree/)|[Solution](../../blob/master/EASY/src/easy/MinimumDepthofBinaryTree.java)| O(n)|O(1)~O(h) | Easy| BFS, DFS
 |91|[Decode Ways](https://leetcode.com/problems/decode-ways/)|[Solution](../../blob/master/MEDIUM/src/medium/DecodeWays.java)| O(n)|O(n) | Medium| DP
 |98|[Validate Binary Search Tree](https://leetcode.com/problems/validate-binary-search-tree/)|[Solution] | O(n) | O(1) | Medium | DFS/Recursion