1

Author: kedebug

PathSum/PathSum.cpp

@@ -0,0 +1,35 @@
+/**
+ * Definition for binary tree
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
+ * };
+ */
+class Solution {
+public:
+    bool hasPathSum(TreeNode *root, int sum) {
+        // Start typing your C/C++ solution below
+        // DO NOT write int main() function
+        if (root == NULL)
+            return false;
+        return dfs(root, 0, sum);
+        
+    }
+    
+    bool dfs(TreeNode *node, int value, int target) {
+        if (node->left == NULL && node->right == NULL) {
+            if (value + node->val == target) 
+                return true;
+            else
+                return false;
+        } 
+        bool flag = false;
+        if (node->left)
+            flag = dfs(node->left, node->val + value, target);
+        if (flag) return true;
+        if (node->right)
+            return dfs(node->right, node->val + value, target);
+    }
+};