Create PathSum.java

PathSum.java

@@ -0,0 +1,37 @@
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     int val;
+ *     TreeNode left;
+ *     TreeNode right;
+ *     TreeNode() {}
+ *     TreeNode(int val) { this.val = val; }
+ *     TreeNode(int val, TreeNode left, TreeNode right) {
+ *         this.val = val;
+ *         this.left = left;
+ *         this.right = right;
+ *     }
+ * }
+ */
+class PathSum {
+/*
+Runtime: 0 ms, faster than 100.00% of Java online submissions for Path Sum.
+Memory Usage: 39.2 MB, less than 35.65% of Java online submissions for Path Sum.
+*/
+    public boolean hasPathSum(TreeNode root, int sum) {
+      if(root==null && sum==0)
+          return false;
+      else
+          return checkSumofPath(root,sum);
+    }
+
+    public boolean checkSumofPath(TreeNode root, int sum)
+    {        
+        if(root==null)
+            return false;
+        if (root.left == null && root.right == null) return sum == root.val;
+
+        return checkSumofPath(root.left,sum-root.val)||checkSumofPath(root.right,sum-root.val);
+
+    }
+}