jianchao_li_高分内容_个人页-阿里云开发者社区

发表了文章 2018-01-02

Jianchao's Blog is gonna to be moved to Yunqi

我的博客即将入驻“云栖社区”，诚邀技术同仁一同入驻。 Hi, Jianchao's Blog is gonna to be moved to the Yunqi Community of Alibaba Cloud. Welcome to join with me :-)

发表了文章 2016-09-10

[LeetCode] Sum of Two Integers

The code is as follows. public class Solution { public int getSum(int a, int b) { return b == 0 ? a : getSum(a ^ b, (a & b)

发表了文章 2016-08-14

[LeetCode] Ransom Note

A very typical application of hash maps. Since I am now learning Java, I code in Java. The following code uses toCharArray() and getOrDefault(), which are learnt from this post.

发表了文章 2015-12-03

[LeetCode] Sparse Matrix Multiplication

Problem Description: Given two sparse matrices A and B, return the result of AB. You may assume that A's column number is equal to B's row number.

发表了文章 2015-11-23

[LeetCode] Range Sum Query - Mutable

This problem requires a new data structure --- Segment Tree. You may use this GeeksforGeeks article to get some ideas of it.

发表了文章 2015-11-20

[LeetCode] Additive Number

Af first I read the title as "Addictive Number". Anyway, this problem can be solved elegantly using recursion.

发表了文章 2015-11-14

[LeetCode] Number of Islands II

Problem Description: A 2d grid map of m rows and n columns is initially filled with water. We may perform an addLand operation which turns the water at position (row, col) into a land.

发表了文章 2015-11-12

[LeetCode] Range Sum Query 2D - Immutable

Very similar to Range Sum Query - Immutable, but we now need to compute a 2d accunulated-sum. In fact, if you work in computer vision, you may know a name for such an array --- Integral Image.

发表了文章 2015-11-10

[LeetCode] Range Sum Query - Immutable

The idea is fairly straightforward: create an array accu that stores the accumulated sum fornums such that accu[i] = nums[0] + .

发表了文章 2015-11-08

[LeetCode] Smallest Rectangle Enclosing Black Pixels

This post shares very detailed explanation of how to use binary search to find the boundaries of the smallest rectangle that encloses the black pixels.

发表了文章 2015-11-05

[LeetCode] Remove Invalid Parentheses

This problem can be solved very elegantly using BFS, as in this post. The code is rewritten below in C++.

发表了文章 2015-11-03

[LeetCode] Longest Increasing Subsequence

A typical O(n^2) solution uses dynamic programming. Let's use lens[j] to denote the length of the LIS ending with nums[j].

发表了文章 2015-10-31

[LeetCode] Bulls and Cows

This problem seems to be easy at the first glance, especially the problem gives a too much simpler example.

发表了文章 2015-10-30

[LeetCode] Binary Tree Longest Consecutive Sequence

Problem Description: Given a binary tree, find the length of the longest consecutive sequence path. The path refers to any sequence of nodes from so...

发表了文章 2015-10-30

[LeetCode] Serialize and Deserialize Binary Tree

I adopt a way similar to that of the OJ to serialize the binary tree. For the following tree, my serialization result is "1,2,3,null,null,4,5," (note the last comma).

发表了文章 2015-10-22

[LeetCode] Best Meeting Point

Problem Description: A group of two or more people wants to meet and minimize the total travel distance.

发表了文章 2015-10-19

[LeetCode] Find Median from Data Stream

This post shares a very nice solution using two heaps: a max heap for the smaller half and a min heap for the larger half.

发表了文章 2015-10-17

[LeetCode] Flip Game II

Problem Description: You are playing the following Flip Game with your friend: Given a string that contains only these two characters: + and -, you a...

发表了文章 2015-10-15

[LeetCode] Flip Game

Problem Description: You are playing the following Flip Game with your friend: Given a string that contains only these two characters: + and -, you a...

发表了文章 2015-10-13

[LeetCode] Nim Game

Haha, an interesting problem. Just try to let your opponent start with a number that is an integer multiple of 4.

发表了文章 2015-10-12

[LeetCode] Word Pattern II

Problem Description: Given a pattern and a string str, find if str follows the same pattern. Here follow means a full match, such that there is a bi...

发表了文章 2015-10-06

[LeetCode] Word Pattern

This problem can be solved in very neat codes (yeah, you will see Stefan posting many nice solutions).

发表了文章 2015-10-04

[LeetCode] Game of Life

A solution using additional spaces to solve a copy of the original board is easy. To get an in-place solution, we need to record the information of state transitions directly in the board.

发表了文章 2015-10-02

[LeetCode] Unique Word Abbreviation

Problem Description: An abbreviation of a word follows the form . Below are some examples of word abbreviations: a) it --> it ...

发表了文章 2015-09-28

[LeetCode] Find the Duplicate Number

There are mainly two solutions to solve this problem. The first one is very clever, using the idea of cycle detection, and runs in O(n) time.

发表了文章 2015-09-24

[LeetCode] Walls and Gates

Problem Description: You are given a m x n 2D grid initialized with these three possible values. -1 - A wall or an obstacle.

发表了文章 2015-09-22

[LeetCode] Inorder Successor in BST

Problem Description: Given a binary search tree and a node in it, find the in-order successor of that node in the BST.

发表了文章 2015-09-21

[LeetCode] Peeking Iterator

An interesting problem about iterators. This post shares a very nice solution, which is rewritten below, with minor simplifications.

发表了文章 2015-09-16

[LeetCode] Expression Add Operators

This post shares a very nice solution, which is rewritten below. 1 class Solution { 2 public: 3 vector addOperators(string num, int target) { 4 int n = num.

发表了文章 2015-09-14

[LeetCode] Zigzag Conversion

The key challenge to this problem is to make the code clean. This post has shared a nice example, which is rewritten below in C++.

发表了文章 2015-09-14

[LeetCode] Zigzag Iterator

Problem Description: Given two 1d vectors, implement an iterator to return their elements alternately.

发表了文章 2015-09-10

[LeetCode] Wiggle Sort

Problem Description: Given an unsorted array nums, reorder it in-place such that nums[0] = nums[2] = nums[i - 1]; If i is even, then nums[i] nums[i...

发表了文章 2015-09-09

[LeetCode] Perfect Squares

Well, after seeing the similar problems, you may have known how to solve this problem. Yeah, just to construct larger numbers from smaller numbers by adding perfect squares to them.

发表了文章 2015-09-08

[LeetCode] Minimum Window Substring

This post shares a nice explanation, which is implemented here. The code is rewritten below. 1 class Solution { 2 public: 3 string minWindow(string s, string t) { 4 int m = s.

发表了文章 2015-09-08

[LeetCode] Valid Sudoku

This problem is relatively easy. The challenge is how to get a concise code. This post shares a very elegant one which traverses each cell of board only once.

发表了文章 2015-09-08

[LeetCode] Sudoku Solver

Just don't be scared by this problem :-) It's also very standard backtracking problem. This post shares a very concise code, which is rewritten below in C++.

发表了文章 2015-09-07

[LeetCode] First Bad Version

Just use binary search to find the first bad version. The code is as follows. 1 // Forward declaration of isBadVersion API.

发表了文章 2015-09-06

[LeetCode] Find the Celebrity

Problem Description: Suppose you are at a party with n people (labeled from 0 to n - 1) and among them, there may exist one celebrity.

发表了文章 2015-09-05

[LeetCode] Paint Fence

Problem Description: There is a fence with n posts, each post can be painted with one of the k colors.

发表了文章 2015-09-04

[LeetCode] H-Index II

This problem is designed specifically to use binary search. In fact, in H-Index, someone has already used this idea (you may refer to this post :-)) The code is as follows.

发表了文章 2015-09-04

[LeetCode] H-Index

If you've read the Wikipedia article of H-Index, there is already a neat formula there for computing the h-index, which is written below using the notations of the problem.

发表了文章 2015-09-02

[LeetCode] Maximal Rectangle

This link shares a nice solution with explanation using DP. You will be clear of the algorithm after running it on its suggested example: matrix = ...

发表了文章 2015-09-01

[LeetCode] Reverse Linked List II

The basic idea is as follows: Create a new_head that points to head and use it to locate the immediate node before them-th (notice that it is 1-inde...

发表了文章 2015-09-01

[LeetCode] Largest Rectangle in Histogram

This link has a very neat code, which is rewritten below using stack since the push and pop operations of it are O(1) time, while the pop_back and push_back of vector tend to be more time-consuming.

发表了文章 2015-08-31

[LeetCode] Integer to English Words

This problem is not difficult. But it is not easy to have a bug-free code. As you write your codes according to the hints, the most important thing is...

发表了文章 2015-08-30

[LeetCode] Closest Binary Search Tree Value II

Problem Description: Given a non-empty binary search tree and a target value, find k values in the BST that are closest to the target.

发表了文章 2015-08-29

[LeetCode] Encode and Decode Strings

Problem Description: Design an algorithm to encode a list of strings to a string. The encoded string is then sent over the network and is decoded back to the original list of strings.

发表了文章 2015-08-28

[LintCode] 第一个错误的代码版本

1 /** 2 * class VersionControl { 3 * public: 4 * static bool isBadVersion(int k); 5 * } 6 * you can use VersionControl::isBa...

发表了文章 2015-08-27

[LeetCode] Dungeon Game

An interesting problem. The code is also short and clear. The basic idea is to use a 2d array dp[i][j] to denote the minimum hp that is required before entering dungeon[i][j].

发表了文章 2015-08-27

[LeetCode] Closest Binary Search Tree Value

Problem Description: Given a non-empty binary search tree and a target value, find the value in the BST that is closest to the target.

热门

活动广场

任务中心

开发者评测

高校计划

乘风者计划

训练营

阿里云MVP

话题

直播

下载

镜像站

技术资料

插件

jianchao_li_个人页

个人介绍

擅长的技术

Jianchao&#39;s Blog is gonna to be moved to Yunqi

[LeetCode] Sum of Two Integers

[LeetCode] Ransom Note

[LeetCode] Sparse Matrix Multiplication

[LeetCode] Range Sum Query - Mutable

[LeetCode] Additive Number

[LeetCode] Number of Islands II

[LeetCode] Range Sum Query 2D - Immutable

[LeetCode] Range Sum Query - Immutable

[LeetCode] Smallest Rectangle Enclosing Black Pixels

[LeetCode] Remove Invalid Parentheses

[LeetCode] Longest Increasing Subsequence

[LeetCode] Bulls and Cows

[LeetCode] Binary Tree Longest Consecutive Sequence

[LeetCode] Serialize and Deserialize Binary Tree

[LeetCode] Best Meeting Point

[LeetCode] Find Median from Data Stream

[LeetCode] Flip Game II

[LeetCode] Flip Game

[LeetCode] Nim Game

[LeetCode] Word Pattern II

[LeetCode] Word Pattern

[LeetCode] Game of Life

[LeetCode] Unique Word Abbreviation

[LeetCode] Find the Duplicate Number

[LeetCode] Walls and Gates

[LeetCode] Inorder Successor in BST

[LeetCode] Peeking Iterator

[LeetCode] Expression Add Operators

[LeetCode] Zigzag Conversion

[LeetCode] Zigzag Iterator

[LeetCode] Wiggle Sort

[LeetCode] Perfect Squares

[LeetCode] Minimum Window Substring

[LeetCode] Valid Sudoku

[LeetCode] Sudoku Solver

[LeetCode] First Bad Version

[LeetCode] Find the Celebrity

[LeetCode] Paint Fence

[LeetCode] H-Index II

[LeetCode] H-Index

[LeetCode] Maximal Rectangle

[LeetCode] Reverse Linked List II

[LeetCode] Largest Rectangle in Histogram

[LeetCode] Integer to English Words

[LeetCode] Closest Binary Search Tree Value II

[LeetCode] Encode and Decode Strings

[LintCode] 第一个错误的代码版本

[LeetCode] Dungeon Game

[LeetCode] Closest Binary Search Tree Value

Jianchao&#39;s Blog is gonna to be moved to Yunqi

[LeetCode] Sum of Two Integers

[LeetCode] Ransom Note

[LeetCode] Sparse Matrix Multiplication

[LeetCode] Range Sum Query - Mutable

[LeetCode] Additive Number

[LeetCode] Number of Islands II

[LeetCode] Range Sum Query 2D - Immutable

[LeetCode] Range Sum Query - Immutable

[LeetCode] Smallest Rectangle Enclosing Black Pixels

[LeetCode] Remove Invalid Parentheses

[LeetCode] Longest Increasing Subsequence

[LeetCode] Bulls and Cows

Jianchao's Blog is gonna to be moved to Yunqi

Jianchao's Blog is gonna to be moved to Yunqi