From 0f2c702ab83a72b7205b5e395883059451f4acc9 Mon Sep 17 00:00:00 2001 From: Havan Date: Tue, 23 Apr 2019 17:54:17 -0700 Subject: [PATCH] Add solution for 951 --- README.md | 1 + .../java/com/fishercoder/solutions/_951.java | 33 +++++++++++++++++ src/test/java/com/fishercoder/_951Test.java | 35 +++++++++++++++++++ 3 files changed, 69 insertions(+) create mode 100644 src/main/java/com/fishercoder/solutions/_951.java create mode 100644 src/test/java/com/fishercoder/_951Test.java diff --git a/README.md b/README.md index 3dac1a1d3e..05b5726101 100644 --- a/README.md +++ b/README.md @@ -50,6 +50,7 @@ Your ideas/fixes/algorithms are more than welcome! |965|[Univalued Binary Tree](https://leetcode.com/problems/univalued-binary-tree/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_965.java) | O(n) | O(h) | |Easy| DFS, recursion| |961|[N-Repeated Element in Size 2N Array](https://leetcode.com/problems/n-repeated-element-in-size-2n-array/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_961.java) | O(n) | O(1) | |Easy| |953|[Verifying an Alien Dictionary](https://leetcode.com/problems/verifying-an-alien-dictionary/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_953.java) | O(1) | O(1) | |Easy| +|951|[Flip Equivalent Binary Trees](https://leetcode.com/problems/flip-equivalent-binary-trees/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_951.java) | O(n) | O(h) | |Medium| Tree, DFS, recursion| |950|[Reveal Cards In Increasing Order](https://leetcode.com/problems/reveal-cards-in-increasing-order/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_950.java) | O(nlogn) | O(n) | |Medium| |944|[Delete Columns to Make Sorted](https://leetcode.com/problems/delete-columns-to-make-sorted/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_944.java) | O(n) | O(1) | |Easy| |942|[DI String Match](https://leetcode.com/problems/di-string-match/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_942.java) | O(n) | O(n) | |Easy| diff --git a/src/main/java/com/fishercoder/solutions/_951.java b/src/main/java/com/fishercoder/solutions/_951.java new file mode 100644 index 0000000000..20ea0da130 --- /dev/null +++ b/src/main/java/com/fishercoder/solutions/_951.java @@ -0,0 +1,33 @@ +package com.fishercoder.solutions; + +import com.fishercoder.common.classes.TreeNode; + +/** + * 951. Flip Equivalent Binary Trees + * + * For a binary tree T, we can define a flip operation as follows: choose any node, and swap the left and right child subtrees. + * + * A binary tree X is flip equivalent to a binary tree Y if and only if we can make X equal to Y after some number of flip operations. + * + * Write a function that determines whether two binary trees are flip equivalent. The trees are given by root nodes root1 and root2. + * + * Note: + * * Each tree will have at most 100 nodes. + * * Each value in each tree will be a unique integer in the range [0, 99]. + */ + +public class _951 { + public static class Solution1 { + public boolean flipEquiv(TreeNode root1, TreeNode root2) { + if (root1 == null && root2 == null) return true; + if (root1 == null || root2 == null) return false; + + if (root1.val != root2.val) return false; + + return ( + (flipEquiv(root1.left, root2.left) && flipEquiv(root1.right, root2.right)) || + (flipEquiv(root1.left, root2.right) && flipEquiv(root1.right, root2.left)) + ); + } + } +} diff --git a/src/test/java/com/fishercoder/_951Test.java b/src/test/java/com/fishercoder/_951Test.java new file mode 100644 index 0000000000..4750a22c18 --- /dev/null +++ b/src/test/java/com/fishercoder/_951Test.java @@ -0,0 +1,35 @@ +package com.fishercoder; + +import com.fishercoder.common.classes.TreeNode; +import com.fishercoder.common.utils.TreeUtils; +import com.fishercoder.solutions._951; +import org.junit.BeforeClass; +import org.junit.Test; + +import java.util.Arrays; + +import static org.junit.Assert.assertFalse; +import static org.junit.Assert.assertTrue; + +public class _951Test { + private static _951.Solution1 solution1; + + @BeforeClass + public static void setup() { + solution1 = new _951.Solution1(); + } + + @Test + public void test1() { + TreeNode root1 = TreeUtils.constructBinaryTree(Arrays.asList(1, 2, 3, 4, 5, 6, null, null, null, 7, 8)); + TreeNode root2 = TreeUtils.constructBinaryTree(Arrays.asList(1, 3, 2, null, 6, 4, 5, null, null, null, null, 8, 7)); + assertTrue(solution1.flipEquiv(root1, root2)); + } + + @Test + public void test2() { + TreeNode root1 = TreeUtils.constructBinaryTree(Arrays.asList(1, 2, 3)); + TreeNode root2 = TreeUtils.constructBinaryTree(Arrays.asList(1, 2, 4)); + assertFalse(solution1.flipEquiv(root1, root2)); + } +} pFad - Phonifier reborn

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