path sum

Author: 石峰铭

.README.md.icloud

@@ -0,0 +1,18 @@
+class TreeNode(object):
+    def __init__(self, x):
+        self.val = x
+        self.left = None
+        self.right = None
+
+class Solution(object):
+    def hasPathSum(self, root, sum):
+        """
+        :type root: TreeNode
+        :type sum: int
+        :rtype: bool
+        """
+        if root == None:
+            return False
+        if sum == root.val and root.left == None and root.right == None:
+            return True
+        return self.hasPathSum(root.left, sum - root.val) or self.hasPathSum(root.right, sum - root.val)

PathSum/PathSum.py

@@ -0,0 +1,45 @@
+//
+//  Leetcode_parctice
+//
+//  Created by PixelShi on 2017/2/8.
+//  Copyright © 2017年 sfmDev. All rights reserved.
+//
+
+import UIKit
+
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     public var val: Int
+ *     public var left: TreeNode?
+ *     public var right: TreeNode?
+ *     public init(_ val: Int) {
+ *         self.val = val
+ *         self.left = nil
+ *         self.right = nil
+ *     }
+ * }
+ */
+
+public class TreeNode {
+     public var val: Int
+     public var left: TreeNode?
+     public var right: TreeNode?
+     public init(_ val: Int) {
+         self.val = val
+         self.left = nil
+         self.right = nil
+     }
+}
+
+class Solution {
+    func hasPathSum(_ root: TreeNode?, _ sum: Int) -> Bool {
+        guard let root = root else {
+            return false
+        }
+        if sum == root.val && root.left == nil && root.right == nil {
+            return true
+        }
+        return hasPathSum(root.left, sum - root.val) || hasPathSum(root.right, sum - root.val)
+    }
+}