day 39: 572-subtree-of-another-tree

572-subtree-of-another-tree/driver.cpp

@@ -0,0 +1,18 @@
+#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);
+	bool answer = true;
+	
+	Solution soln;
+	cout << "Checked subtree correctly? " << soln.test(&n4, &n7, answer) << endl;
+	return 0;
+}

572-subtree-of-another-tree/soln.cpp

@@ -0,0 +1,37 @@
+#include "soln.hpp"
+
+bool Solution::isIdenticalTree(TreeNode *t1, TreeNode *t2)
+{
+	if (!t1 || !t2)
+	{
+		return t1 == nullptr && t2 == nullptr;
+	}
+	else if (t1->val == t2->val)
+	{
+		return isIdenticalTree(t1->left, t2->left) && isIdenticalTree(t1->right, t2->right);
+	}
+	else
+	{
+		return false;
+	}
+}
+bool Solution::isSubtree(TreeNode *root, TreeNode *subRoot)
+{
+	if (!root)
+	{
+		return false;
+	}
+	else if (isIdenticalTree(root, subRoot))
+	{
+		return true;
+	}
+	else
+	{
+		return isSubtree(root->left, subRoot) || isSubtree(root->right, subRoot);
+	}
+}
+
+bool Solution::test(TreeNode *root, TreeNode *subRoot, bool answer)
+{
+	return isSubtree(root, subRoot) == answer;
+}

572-subtree-of-another-tree/soln.hpp

@@ -0,0 +1,20 @@
+#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:
+	bool isIdenticalTree(TreeNode *t1, TreeNode *t2);
+	bool isSubtree(TreeNode *root, TreeNode *subRoot);
+	bool test(TreeNode *root, TreeNode *subRoot, bool answer);
+};