数据结构与算法----递归 - 随笔分类 - PJCK

(BFS DFS 并查集) leetcode 547. Friend Circles

摘要：There are N students in a class. Some of them are friends, while some are not. Their friendship is transitive in nature. For example, if A is a direct 阅读全文

posted @ 2019-05-17 16:27 PJCK 阅读(247) 评论(0) 推荐(0)

(N叉树递归) leetcode 590. N-ary Tree Postorder Traversal

摘要：Given an n-ary tree, return the postorder traversal of its nodes' values. For example, given a 3-ary tree: Return its postorder traversal as: [5,6,3,2 阅读全文

posted @ 2019-04-26 19:15 PJCK 阅读(247) 评论(0) 推荐(0)

(N叉树递归) leetcode589. N-ary Tree Preorder Traversal

摘要：Given an n-ary tree, return the preorder traversal of its nodes' values. For example, given a 3-ary tree: Return its preorder traversal as: [1,3,5,6,2 阅读全文

posted @ 2019-04-26 19:12 PJCK 阅读(154) 评论(0) 推荐(0)

(N叉树 DFS 递归 BFS) leetcode 559. Maximum Depth of N-ary Tree

摘要：Given a n-ary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path from the root node down to the farthest le 阅读全文

posted @ 2019-04-26 18:44 PJCK 阅读(112) 评论(0) 推荐(0)

(BST 递归) leetcode98. Validate Binary Search Tree

摘要：Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains only 阅读全文

posted @ 2019-04-26 16:07 PJCK 阅读(199) 评论(0) 推荐(0)

(二叉树递归) leetcode 145. Binary Tree Postorder Traversal

摘要：Given a binary tree, return the postorder traversal of its nodes' values. Example: Follow up: Recursive solution is trivial, could you do it iterative 阅读全文

posted @ 2019-04-26 13:18 PJCK 阅读(95) 评论(0) 推荐(0)

(二叉树递归) leetcode94. Binary Tree Inorder Traversal

摘要：Given a binary tree, return the inorder traversal of its nodes' values. Example: Follow up: Recursive solution is trivial, could you do it iteratively 阅读全文

posted @ 2019-04-26 13:13 PJCK 阅读(86) 评论(0) 推荐(0)

(二叉树递归) leetcode 889. Construct Binary Tree from Preorder and Postorder Traversal

摘要：Return any binary tree that matches the given preorder and postorder traversals. Values in the traversals pre and post are distinct positive integers. 阅读全文

posted @ 2019-04-26 10:35 PJCK 阅读(200) 评论(0) 推荐(0)

(二叉树递归) leetcode 105. Construct Binary Tree from Preorder and Inorder Traversal

摘要：Given preorder and inorder traversal of a tree, construct the binary tree. Note:You may assume that duplicates do not exist in the tree. For example, 阅读全文

posted @ 2019-04-26 09:12 PJCK 阅读(152) 评论(0) 推荐(0)

(二叉树递归) leetcode 106. Construct Binary Tree from Inorder and Postorder Traversal

摘要：Given inorder and postorder traversal of a tree, construct the binary tree. Note:You may assume that duplicates do not exist in the tree. For example, 阅读全文

posted @ 2019-04-26 09:09 PJCK 阅读(187) 评论(0) 推荐(0)

(字符串数组递归双指针) leetcode 344. Reverse String

摘要：Write a function that reverses a string. The input string is given as an array of characters char[]. Do not allocate extra space for another array, yo 阅读全文

posted @ 2019-04-19 20:47 PJCK 阅读(122) 评论(0) 推荐(0)

(二叉树 DFS 递归) leetcode 112. Path Sum

摘要：Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum. N 阅读全文

posted @ 2019-04-19 20:38 PJCK 阅读(165) 评论(0) 推荐(0)

(二叉树 DFS 递归) leetcode 101. Symmetric Tree

摘要：Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree [1,2,2,3,4,4,3] is symmet 阅读全文

posted @ 2019-04-19 20:28 PJCK 阅读(107) 评论(0) 推荐(0)

(二叉树递归) leetcode 144. Binary Tree Preorder Traversal

摘要：Given a binary tree, return the preorder traversal of its nodes' values. Example: Follow up: Recursive solution is trivial, could you do it iterativel 阅读全文

posted @ 2019-04-17 18:43 PJCK 阅读(174) 评论(0) 推荐(0)

(二叉树递归 DFS) leetcode 100. Same Tree

摘要：Given two binary trees, write a function to check if they are the same or not. Two binary trees are considered the same if they are structurally ident 阅读全文

posted @ 2019-04-17 17:35 PJCK 阅读(100) 评论(0) 推荐(0)

(二叉树 BFS DFS) leetcode 104. Maximum Depth of Binary Tree

摘要：Given a binary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path from the root node down to the farthest l 阅读全文

posted @ 2019-04-16 09:24 PJCK 阅读(129) 评论(0) 推荐(0)

(二叉树 BFS DFS) leetcode 111. Minimum Depth of Binary Tree

摘要：Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest l 阅读全文

posted @ 2019-04-16 09:20 PJCK 阅读(138) 评论(0) 推荐(0)

(链表递归) leetcode 24. Swap Nodes in Pairs

摘要：Given a linked list, swap every two adjacent nodes and return its head. You may not modify the values in the list's nodes, only nodes itself may be ch 阅读全文

posted @ 2019-04-14 10:29 PJCK 阅读(250) 评论(0) 推荐(0)

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随笔分类 - 数据结构与算法----递归