day 27: 226-invert-binary-tree, 11-container-with-most-water

226-invert-binary-tree/driver.cpp

@@ -0,0 +1,26 @@
+#include "soln.hpp"
+
+int main()
+{
+	// input
+	TreeNode n1 = TreeNode(1);
+	TreeNode n3 = TreeNode(3);
+	TreeNode n6 = TreeNode(6);
+	TreeNode n9 = TreeNode(9);
+	TreeNode n2 = TreeNode(2, &n1, &n3);
+	TreeNode n7 = TreeNode(7, &n6, &n9);
+	TreeNode n4 = TreeNode(4, &n2, &n7);
+	// answer
+	TreeNode n_9 = TreeNode(9);
+	TreeNode n_6 = TreeNode(6);
+	TreeNode n_3 = TreeNode(3);
+	TreeNode n_1 = TreeNode(1);
+	TreeNode n_7 = TreeNode(7, &n_9, &n_6);
+	TreeNode n_2 = TreeNode(2, &n_3, &n_1);
+	TreeNode n_4 = TreeNode(4, &n_7, &n_2);
+
+	Solution soln;
+	TreeNode *solved_n4 = soln.invertTree(&n4);
+	cout << "Inverted binary tree correctly? " << soln.test(solved_n4, &n_4) << endl;
+	return 0;
+}

226-invert-binary-tree/soln.cpp

@@ -0,0 +1,31 @@
+#include "soln.hpp"
+
+TreeNode *Solution::invertTree(TreeNode *root)
+{
+	if (root != nullptr)
+	{
+		TreeNode *tmp = root->left;
+		root->left = root->right;
+		root->right = tmp;
+		invertTree(root->left);
+		invertTree(root->right);
+	}
+	return root;
+}
+
+bool Solution::test(TreeNode *solved_root, TreeNode *answer)
+{
+	if(solved_root == nullptr && answer == nullptr)	{
+		return true;
+	}
+	if (solved_root != nullptr && answer != nullptr)
+	{
+		if (solved_root->val != answer->val)
+		{
+			return false;
+		}
+		return Solution::test(solved_root->left, answer->left) && Solution::test(solved_root->right, answer->right);
+	} else	{
+		return false;
+	}
+}

226-invert-binary-tree/soln.hpp

@@ -0,0 +1,19 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+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);
+	bool test(TreeNode *root, TreeNode *answer);
+};