create path-sum.java

Author: sujin0529

Java/path-sum.java

@@ -0,0 +1,40 @@
+/**
+ * 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 Solution {
+    public boolean hasPathSum(TreeNode root, int sum) {
+        if(root == null){
+            // exception
+            return false;
+        }
+        if(root.left == null && root.right == null){
+            if(sum == root.val){
+                return true;
+            }
+            return false;
+        }
+        else{
+            boolean left = false;
+            boolean right = false;
+            if(root.left != null){
+                left = hasPathSum(root.left, sum-root.val);
+            }
+            if(root.right != null){
+                right = hasPathSum(root.right, sum-root.val);
+            }
+            return left||right;
+        }
+    }
+}