Merge pull request #2609 from markwang1992/112-hasPathSum

112.路径总和增加Go递归法

Author: youngyangyang04

problems/0112.路径总和.md

@@ -727,6 +727,48 @@ class Solution:
 
 ```go
 //递归法
+/**
+ * Definition for a binary tree node.
+ * type TreeNode struct {
+ *     Val int
+ *     Left *TreeNode
+ *     Right *TreeNode
+ * }
+ */
+func hasPathSum(root *TreeNode, targetSum int) bool {
+    if root == nil {
+        return false
+    }
+    return traversal(root, targetSum - root.Val)
+}
+
+func traversal(cur *TreeNode, count int) bool {
+    if cur.Left == nil && cur.Right == nil && count == 0 {
+        return true
+    }
+    if cur.Left == nil && cur.Right == nil {
+        return false
+    }
+    if cur.Left != nil {
+        count -= cur.Left.Val
+        if traversal(cur.Left, count) {
+            return true
+        }
+        count += cur.Left.Val
+    }
+    if cur.Right != nil {
+        count -= cur.Right.Val
+        if traversal(cur.Right, count) {
+            return true
+        }
+        count += cur.Right.Val
+    }
+    return false
+}
+```
+
+```go
+//递归法精简
 /**
  * Definition for a binary tree node.
  * type TreeNode struct {