add: 220516-CN [cpp]

cpp/2205/220516-CN.cpp

@@ -0,0 +1,36 @@
+#include <iostream>
+
+struct TreeNode {
+	int val;
+	TreeNode* left;
+	TreeNode* right;
+	explicit TreeNode(int x, TreeNode* left = nullptr, TreeNode* right = nullptr) : val(x), left(left), right(right) {}
+};
+
+/**
+ * 面试题 04.06. Successor LCCI
+ * Write an algorithm to find the "next" node (i.e., in-order successor) of a given node in a binary search tree.
+ * Return null if there's no "next" node for the given node.
+ */
+
+class Solution {
+public:
+	static TreeNode* inorderSuccessor(TreeNode* root, TreeNode* p) {
+		if (!root || !p)
+			return nullptr;
+		// Target value: p->val;
+		TreeNode* ret = nullptr;
+		for (auto* ptr = root; ptr; ) {
+			if (ptr->val == p->val) {
+				for (ptr = ptr->right; ptr && ptr->left; ptr = ptr->left);
+				return ptr ? ptr : ret;
+			} else if (ptr->val < p->val) {
+				ptr = ptr->right;
+			} else {
+				ret = ptr;
+				ptr = ptr->left;
+			}
+		}
+		return ret;
+	}
+};

cpp/2205/CMakeLists.txt

@@ -3,4 +3,4 @@ PROJECT(2205)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2205 220516.cpp)
+ADD_EXECUTABLE(2205 220516-CN.cpp)