dyllanzhou的专栏

Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.For example, given n = 3, a solution set is:"((()))", "(()())", "(())()", "()(())", "()()()"

There are a row of n houses, each house can be painted with one of the three colors: red, blue or green. The cost of painting each house with a certain color is different. You have to paint all the ho

Given a binary tree struct TreeLinkNode { TreeLinkNode *left; TreeLinkNode *right; TreeLinkNode *next; }Populate each next pointer to point to its next right node. If the

Given a collection of numbers that might contain duplicates, return all possible unique permutations.For example,[1,1,2] have the following unique permutations:[1,1,2], [1,2,1], and [2,1,1].

Given preorder and inorder traversal of a tree, construct the binary tree.Note:You may assume that duplicates do not exist in the tree./** * Definition for a binary tree node. * struct Tre

Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST./** * Definition for singly-linked list. * struct ListNode { * int val; * Lis

Given a digit string, return all possible letter combinations that the number could represent.A mapping of digit to letters (just like on the telephone buttons) is given below.Input:Digit string

The n-queens puzzle is the problem of placing n queens on ann×n chessboard such that no two queens attack each other.Given an integer n, return all distinct solutions to the n-queens puzzle.Ea

Follow up for N-Queens problem.Now, instead outputting board configurations, return the total number of distinct solutions.class Solution {public: /*algorithm: DFS */ vectorgetNex

Additive number is a string whose digits can form additive sequence.A valid additive sequence should contain at least three numbers. Except for the first two numbers, each subsequent number in the s

Given a string S and a string T, count the number of distinct subsequences ofT in S.A subsequence of a string is a new string which is formed from the original string by deleting some (can be none

Remove the minimum number of invalid parentheses in order to make the input string valid. Return all possible results.Note: The input string may contain letters other than the parentheses ( and).

Write a program to solve a Sudoku puzzle by filling the empty cells.Empty cells are indicated by the character '.'.You may assume that there will be only one unique solution.A sudoku puzzle.

Given an array where elements are sorted in ascending order, convert it to a height balanced BST./** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left;

Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum.For example:Given the below binary tree and sum = 22, 5 / \

Given a collection of numbers, return all possible permutations.For example,[1,2,3] have the following permutations:[1,2,3], [1,3,2], [2,1,3], [2,3,1],[3,1,2], and [3,2,1].class Solution

Given a collection of candidate numbers (C) and a target number (T), find all unique combinations inC where the candidate numbers sums to T.Each number in C may only be used once in the combinatio

Clone an undirected graph. Each node in the graph contains a label and a list of itsneighbors.OJ's undirected graph serialization:Nodes are labeled uniquely.We use # as a separator for each

Given a 2d grid map of '1's (land) and '0's (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume

Given two integers n and k, return all possible combinations ofk numbers out of 1 ... n.For example,If n = 4 and k = 2, a solution is:[ [2,4], [3,4], [2,3], [1,2], [1,3], [1,4],]

Given a string s and a dictionary of words dict, determine ifs can be segmented into a space-separated sequence of one or more dictionary words.For example, givens = "leetcode",dict = ["leet",

Given inorder and postorder traversal of a tree, construct the binary tree.Note:You may assume that duplicates do not exist in the tree./** * Definition for a binary tree node. * struct Tr

Given a string s, partition s such that every substring of the partition is a palindrome.Return the minimum cuts needed for a palindrome partitioning of s.For example, given s = "aab",Return 1 s

There are a row of n houses, each house can be painted with one of the k colors. The cost of painting each house with a certain color is different. You have to paint all the houses such that no two ad

Given a positive integer n, find the least number of perfect square numbers (for example,1, 4, 9, 16, ...) which sum to n.For example, given n = 12, return 3 because12 = 4 + 4 + 4; given n = 13,

Given an array of non-negative integers, you are initially positioned at the first index of the array.Each element in the array represents your maximum jump length at that position.Determine if

Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to check whether these edges make up a valid tree.For example:Given n =

Given an integer matrix, find the length of the longest increasing path.From each cell, you can either move to four directions: left, right, up or down. You may NOT move diagonally or move outside o