add: 220524-CN [cpp]

cpp/2205/220524-CN.cpp

@@ -0,0 +1,27 @@
+#include <functional>
+
+struct TreeNode {
+	int val;
+	TreeNode* left;
+	TreeNode* right;
+
+	explicit TreeNode(int x = 0, TreeNode* l = nullptr, TreeNode* r = nullptr) : val(x), left(l), right(r) {}
+};
+
+/**
+ * 965. Univalued Binary Tree
+ * A binary tree is uni-valued if every node in the tree has the same value.
+ * Given the root of a binary tree, return true if the given tree is uni-valued, or false otherwise.
+ */
+
+class Solution {
+public:
+	static bool isUnivalTree(TreeNode* root) {
+		if (!root)
+			return true;
+		std::function<bool(const TreeNode*)> dfs = [&](const TreeNode* ptr) {
+			return !ptr || (ptr->val == root->val && dfs(ptr->left) && dfs(ptr->right));
+		};
+		return dfs(root->left) && dfs(root->right);
+	}
+};

cpp/2205/CMakeLists.txt

@@ -3,4 +3,4 @@ PROJECT(2205)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2205 220523.cpp)
+ADD_EXECUTABLE(2205 220524-CN.cpp)