泉山绿树的博客

Binary Tree Zigzag Level Order Traversal My Submissions Question Total Accepted: 47731 Total Submissions: 176275 Difficulty: Medium Given a binary tree, return the zigzag level order traversal of its

Reverse Words in a String My Submissions Question Total Accepted: 84277 Total Submissions: 546781 Difficulty: Medium Given an input string, reverse the string word by word.For example, Given s = “th

**Perfect Squares My Submissions Question Total Accepted: 16355 Total Submissions: 55778 Difficulty: Medium Given a positive integer n, find the least number of perfect square numbers (for example, 1

Search for a Range My Submissions Question Total Accepted: 64904 Total Submissions: 232560 Difficulty: Medium Given a sorted array of integers, find the starting and ending position of a given target

Range Sum Query 2D - Immutable Total Accepted: 4160 Total Submissions: 20469 Difficulty: MediumGiven a 2D matrix matrix, find the sum of the elements inside the rectangle defined by its upper left cor

Binary Tree Right Side View My Submissions Question Total Accepted: 26870 Total Submissions: 87779 Difficulty: Medium Given a binary tree, imagine yourself standing on the right side of it, return th

Search a 2D Matrix II My Submissions Question Total Accepted: 19946 Total Submissions: 64757 Difficulty: Medium Write an efficient algorithm that searches for a value in an m x n matrix. This matrix

Convert Sorted Array to Binary Search Tree My Submissions Question Total Accepted: 57734 Total Submissions: 165322 Difficulty: Medium Given an array where elements are sorted in ascending order, conv

Product of Array Except Self My Submissions Question Total Accepted: 21825 Total Submissions: 57345 Difficulty: Medium Given an array of n integers where n > 1, nums, return an array output such that

Course Schedule II My Submissions Question Total Accepted: 16442 Total Submissions: 80267 Difficulty: Medium There are a total of n courses you have to take, labeled from 0 to n - 1.Some courses may

Construct Binary Tree from Inorder and Postorder Traversal My Submissions Question Total Accepted: 44071 Total Submissions: 159513 Difficulty: Medium Given inorder and postorder traversal of a tree,

Word Search Total Accepted: 58219 Total Submissions: 270800 Difficulty: MediumGiven a 2D board and a word, find if the word exists in the grid.The word can be constructed from letters of sequentially

Rotate List Total Accepted: 55147 Total Submissions: 249704 Difficulty: MediumGiven a list, rotate the list to the right by k places, where k is non-negative.For example: Given 1->2->3->4->5->NULL an

3Sum Closest My Submissions Question Total Accepted: 58639 Total Submissions: 212334 Difficulty: Medium Given an array S of n integers, find three integers in S such that the sum is closest to a give

Rectangle Area Total Accepted: 24959 Total Submissions: 89043 Difficulty: EasyFind the total area covered by two rectilinear rectangles in a 2D plane.Each rectangle is defined by its bottom left corne

Evaluate Reverse Polish Notation Total Accepted: 55506 Total Submissions: 249113 Difficulty: MediumEvaluate the value of an arithmetic expression in Reverse Polish Notation.Valid operators are +, -, *

Longest Palindromic Substring Total Accepted: 82394 Total Submissions: 381112 Difficulty: MediumGiven a string S, find the longest palindromic substring in S. You may assume that the maximum length of

Decode Ways Total Accepted: 55623 Total Submissions: 331926 Difficulty: MediumA message containing letters from A-Z is being encoded to numbers using the following mapping:‘A’ -> 1 ‘B’ -> 2 … ‘Z’ -

Bulls and Cows Total Accepted: 10932 Total Submissions: 42057 Difficulty: EasyYou are playing the following Bulls and Cows game with your friend: You write down a number and ask your friend to guess w

Range Sum Query - Immutable Total Accepted: 9791 Total Submissions: 40927 Difficulty: EasyGiven an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive.Example:G

House Robber Total Accepted: 45703 Total Submissions: 142461 Difficulty: EasyYou are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the

Bulb Switcher Total Accepted: 970 Total Submissions: 2597 Difficulty: MediumThere are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the thi

Sqrt(x) Total Accepted: 74812 Total Submissions: 310770 Difficulty: MediumImplement int sqrt(int x).Compute and return the square root of x.Subscribe to see which companies asked this question题目很简单，弄清

House Robber II Total Accepted: 18212 Total Submissions: 63419 Difficulty: MediumNote: This is an extension of House Robber.After robbing those houses on that street, the thief has found himself a new

Remove Duplicates from Sorted List II Total Accepted: 58686 Total Submissions: 228299 Difficulty: MediumGiven a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct

Populating Next Right Pointers in Each Node My Submissions Question Total Accepted: 72104 Total Submissions: 198545 Difficulty: Medium Given a binary treestruct TreeLinkNode { TreeLinkNode *left;

Search in Rotated Sorted Array My Submissions Question Total Accepted: 78974 Total Submissions: 271221 Difficulty: Hard Suppose a sorted array is rotated at some pivot unknown to you beforehand.(i.e.

LeetCode OJ LeetCode Premium Subscription Problems Pick One! Courses Discuss Book WooStam Combination Sum III My Submissions Question Total Accepted: 17981 Total Submissions: 56703 Difficult

细节实现题，在纸上画了一会才AC/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */class Solution {public:

中午吃东西时候看到这道题有个奇妙的解法挺好玩，求字符串“abcd”的全部组合。 输入：“abcd” 输出：”a”,”b”,”c”,”d”,”ab”,”ac”,”ad”,”bc”,”bd”,”cd”,”abc”,”abd”,”acd”,”bcd”,”abcd”。当然不要求顺序也完全相同。以往的想法是通过深度优先搜索，用递归实现，思路比较常见。但是中午大神给出的这种想法是生成(2^n) - 1个数字

/** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class

慢方法class Solution {public: void moveZeroes(vector<int>& nums) { for(int i = 0;i != nums.size();++i){ if(nums[i] == 0){ for(int j = i + 1;j != nums.size();++j){

#include <iostream>using namespace std;void exchange(int& x, int& y){ int tem = x; x = y; y = tem;} int par(int a[],int b,int e){ int x = a[b]; int j = b + 1; int i = b; f

这道应该是最经典的一道题了吧class Solution {public: int myAtoi(string str) { int n = str.size(); long long num = 0; int sig = 1; int i = 0; while(str[i] == ' ' && i < n)

class Solution {public: bool isBalanced(TreeNode* root) { if(root == nullptr) return true; stack<TreeNode*> sT; TreeNode* t = root; while(!sT.empty() || t){

#include <iostream>#include <vector>using namespace std;vector<string> func(size_t n){ vector<string> res{}; if(n == 0) return res; if(n == 1){ res = {"0","1"}; return res

#include <iostream>using namespace std;#define len 5 void countSorting(int A[],int B[],int k ){ int C[k + 1] = {0}; for(size_t i = 0;i != len;++i) ++C[A[i]]; for(size_t i = 1 ;i !=

算法导论的快排算法，#include <iostream>using namespace std;int a[] = {9};void exchange(int& x, int& y){ int tem = x; x = y; y = tem;}int par(int a[],int b,int e){ int x = a[b]; int j = b +

当然是伪码，自己在纸上模拟了一遍是没错的。如果发现什么错误欢迎指正。N_DFS(gragh g, int i){ int j; seqstack s; INITSTACK(s); while(!EMPTY(s)){ if(visited[i] == 0){ visited[i] = 1; printf(g

假设在n进制下，下面的等式成立，n的值是（），567*456=150216.完全是考数学的题目：http://topic.youkuaiyun.com/u/20100319/14/ffd0920a-b256-48d8-8d86-da36a3bfab8d.html做不出来也就算了，实际上,IT公司好多这样子的题目（腾讯除外），难怪考出来，成绩很差都可以进面试。这道题是google和淘宝的笔试题目，没事看看，确实很