feat: 添加多个二叉树相关算法的实现，包括层序遍历、翻转二叉树和中序遍历

Author: tkzzzzzz6

acwing/test.go

@@ -0,0 +1,5 @@
+import fmt
+
+int main(){
+	return 0; 
+}

leetcode/problems/102.binary-tree-level-order-traversal.cpp

@@ -0,0 +1,82 @@
+/*
+ * @lc app=leetcode.cn id=102 lang=cpp
+ * @lcpr version=30204
+ *
+ * [102] 二叉树的层序遍历
+ */
+
+// @lcpr-template-start
+using namespace std;
+#include <algorithm>
+#include <array>
+#include <bitset>
+#include <climits>
+#include <deque>
+#include <functional>
+#include <iostream>
+#include <list>
+#include <queue>
+#include <stack>
+#include <tuple>
+#include <unordered_map>
+#include <unordered_set>
+#include <utility>
+#include <vector>
+// @lcpr-template-end
+// @lc code=start
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left),
+ * right(right) {}
+ * };
+ */
+class Solution {
+public:
+  vector<vector<int>> levelOrder(TreeNode *root) {
+    vector<vector<int>> res;
+    if (!root)
+      return res;
+
+    queue<TreeNode *> q;
+    q.push(root);
+
+    while (!q.empty()) {
+      int size = q.size();
+      vector<int> line;
+      while (size--) {
+        auto t = q.front();
+        line.push_back(t->val);
+        q.pop();
+        if (t->left)
+          q.push(t->left);
+        if (t->right)
+          q.push(t->right);
+      }
+      res.push_back(line);
+      line.clear();
+    }
+    return res;
+  }
+};
+// @lc code=end
+
+/*
+// @lcpr case=start
+// [3,9,20,null,null,15,7]\n
+// @lcpr case=end
+
+// @lcpr case=start
+// [1]\n
+// @lcpr case=end
+
+// @lcpr case=start
+// []\n
+// @lcpr case=end
+
+ */

leetcode/problems/226.invert-binary-tree.cpp

@@ -0,0 +1,93 @@
+/*
+ * @Author: tkzzzzzz6
+ * @Date: 2026-04-23 15:04:03
+ * @LastEditors: tkzzzzzz6
+ * @LastEditTime: 2026-04-23 15:44:44
+ */
+/*
+ * @lc app=leetcode.cn id=226 lang=cpp
+ * @lcpr version=30204
+ *
+ * [226] 翻转二叉树
+ */
+
+// @lcpr-template-start
+using namespace std;
+#include <algorithm>
+#include <array>
+#include <bitset>
+#include <climits>
+#include <deque>
+#include <functional>
+#include <iostream>
+#include <list>
+#include <queue>
+#include <stack>
+#include <tuple>
+#include <unordered_map>
+#include <unordered_set>
+#include <utility>
+#include <vector>
+// @lcpr-template-end
+// @lc code=start
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left),
+ * right(right) {}
+ * };
+ */
+class Solution {
+   public:
+    TreeNode *invertTree(TreeNode *root) {
+        if (!root)
+            return root;
+
+        // 前序遍历
+        // swap(root->left, root->right);
+        // invertTree(root->left);
+        // invertTree(root->right);
+        // 后序遍历
+        // invertTree(root->left);
+        // invertTree(root->right);
+        // swap(root->left, root->right);
+        // // 中序遍历
+        // invertTree(root->left);
+        // swap(root->left, root->right);
+        // invertTree(root->left);
+        // // 层次遍历
+        queue<TreeNode *> q;
+        q.push(root);
+        while (!q.empty()) {
+            auto t = q.front();
+            q.pop();
+            swap(t->left, t->right);
+            if (t->left)
+                q.push(t->left);
+            if (t->right)
+                q.push(t->right);
+        }
+        return root;
+    }
+};
+// @lc code=end
+
+/*
+// @lcpr case=start
+// [4,2,7,1,3,6,9]\n
+// @lcpr case=end
+
+// @lcpr case=start
+// [2,1,3]\n
+// @lcpr case=end
+
+// @lcpr case=start
+// []\n
+// @lcpr case=end
+
+ */

leetcode/problems/94.binary-tree-inorder-traversal-2.cpp

@@ -0,0 +1,80 @@
+/*
+ * @Author: tkzzzzzz6
+ * @Date: 2026-04-22 00:17:58
+ * @LastEditors: tkzzzzzz6
+ * @LastEditTime: 2026-04-23 14:21:14
+ */
+/*
+ * @lc app=leetcode.cn id=94 lang=cpp
+ * @lcpr version=30204
+ *
+ * [94] 二叉树的中序遍历
+ */
+
+// @lcpr-template-start
+using namespace std;
+#include <algorithm>
+#include <array>
+#include <bitset>
+#include <climits>
+#include <deque>
+#include <functional>
+#include <iostream>
+#include <list>
+#include <queue>
+#include <stack>
+#include <tuple>
+#include <unordered_map>
+#include <unordered_set>
+#include <utility>
+#include <vector>
+// @lcpr-template-end
+// @lc code=start
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
+ * };
+ */
+class Solution {
+   public:
+    vector<int> inorderTraversal(TreeNode *root) {
+        vector<int> res;
+        auto cur = root;
+        stack<TreeNode *> st;
+
+        while (cur || !st.empty()) {
+            if (cur) {
+                st.push(cur);
+                cur = cur->left;
+            } else {
+                cur = st.top();
+                st.pop();
+                res.push_back(cur->val);
+                cur = cur->right;
+            }
+        }
+        return res;
+    }
+};
+// @lc code=end
+
+/*
+// @lcpr case=start
+// [1,null,2,3]\n
+// @lcpr case=end
+
+// @lcpr case=start
+// []\n
+// @lcpr case=end
+
+// @lcpr case=start
+// [1]\n
+// @lcpr case=end
+
+ */