猪の成长日记

题目描述Given n points on a 2D plane, find the maximum number of points that lie on the same straight line.我的想法：1、算法设计很简单的题目，但是真正用数据结构实现起来却不容易的一道题。2、刚开始考虑分三类进行解决，一类横坐标相同，一类纵坐标相同的点，一类斜率点3、考...

In LeetCode Store, there are some kinds of items to sell. Each item has a price.However, there are some special offers, and a special offer consists of one or more different kinds of items with a sa...

There are N rooms and you start in room 0.Each room has a distinct number in 0, 1, 2, ..., N-1, and each room may havesome keys to access the next room.Formally, each room ihas a list of keys r...

You need to find the largest value in each row of a binary tree.Example:Input: 1 / \ 3 2 / \ \ 5 3 9Output: [1, 3, 9]来源：力扣（LeetCode）链接：http...

Alex and Lee play a game with piles of stones.There are an even number ofpiles arranged in a row, and each pile has a positive integer number of stones piles[i].The objective of the game is to en...

Given an integer n, generate all structurally unique BST's (binary search trees) that store values 1 ...n.Example:Input: 3Output:[[1,null,3,2],[3,2,null,1],[3,1,null,null,2],[2,1,3]...

On a staircase, the i-th step has some non-negative cost cost[i] assigned (0 indexed).Once you pay the cost, you can either climb one or two steps. You need to find minimum cost to reach the top of ...

A sequence of number is called arithmetic if it consists of at least three elements and if the difference between any two consecutive elements is the same.For example, these are arithmetic sequence:...

Given a square array of integers A, we want the minimum sum of a falling path through A.A falling path starts at any element in the first row, and chooses one element from each row.The next row's ...

Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, ...) which sum to n.Example 1:Input: n = 12Output: 3Explanation: 12 = 4 + 4 + 4.Example 2...

A message containing letters from A-Z is being encoded to numbers using the following mapping:'A' -> 1'B' -> 2...'Z' -> 26Given a non-empty string containing only digits, determine the ...

Given a 2D matrix matrix, find the sum of the elements inside the rectangle defined by its upper left corner (row1, col1) and lower right corner (row2, col2).The above rectangle (with the red borde...

Given an unsorted array of integers, find the length of longest increasing subsequence.Example:Input: [10,9,2,5,3,7,101,18]Output: 4Explanation: The longest increasing subsequence is [2,3,7,101...

Given n, how many structurally unique BST's (binary search trees) that store values 1 ...n?Example:Input: 3Output: 5Explanation:Given n = 3, there are a total of 5 unique BST's: 1 ...

Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.Note: You can only move either down or right at a...

Your are given an array of integers prices, for which the i-th element is the price of a given stock on day i; and a non-negative integer fee representing a transaction fee.You may complete as many ...

Given a positive integer n, break it into the sum of at least two positive integers and maximize the product of those integers. Return the maximum product you can get.Example 1:Input: 2Output: 1...

You have a list ofwords and a pattern, and you want to know which words in words matches the pattern.A word matches the pattern if there exists a permutation of letters p so that after replacing ev...

We have a sequence of books: the i-th book has thickness books[i][0] and height books[i][1].We want to place these books in order onto bookcase shelves that have total width shelf_width.We choose ...

题目描述Evaluate the value of an arithmetic expression in Reverse Polish Notation.Valid operators are+,-,*,/. Each operand may be an integer or another expression.Some examples: ["2", "1", "+...

Say you have an array for which the ith element is the price of a given stock on day i.Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy one ...

Given a string s and a string t, check if s is subsequence of t.You may assume that there is only lower case English letters in both s and t. t is potentially a very long (length ~= 500,000) string,...

Given a non-empty string s and a dictionary wordDict containing a list of non-empty words, determine if s can be segmented into a space-separated sequence of one or more dictionary words.Note:The ...

Given an array nums of integers, you can perform operations on the array.In each operation, you pick any nums[i] and delete it to earn nums[i] points. After, you must delete every element equal to n...

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 friend of B, and B is a direct friend of C, then ...

On a 2D plane, we place stones at some integer coordinate points.Each coordinate point may have at most one stone.Now, a move consists of removing a stonethat shares a column or row with another ...

Input: nums is [1, 1, 1, 1, 1], S is 3.Output: 5Explanation:-1+1+1+1+1 = 3+1-1+1+1+1 = 3+1+1-1+1+1 = 3+1+1+1-1+1 = 3+1+1+1+1-1 = 3There are 5 ways to assign symbols to make the sum of nums...

Compare two version numbers version1 and version2.If version1 > version2 return 1;if version1 < version2 return -1;otherwise return 0.You may assume that the version strings are non-empty an...

You are given n pairs of numbers. In every pair, the first number is always smaller than the second number.Now, we define a pair (c, d) can follow another pair (a, b) if and only if b < c. Chain ...

In a country popular for train travel, youhave planned some train travelling one year in advance.The days of the year that you will travel is given as an array days.Each day is an integer from 1 ...

The thief has found himself a new place for his thievery again. There is only one entrance to this area, called the "root." Besides the root, each house has one and only one parent house. After a tour...

Given a non-empty 2D array grid of 0's and 1's, an island is a group of 1's (representing land) connected 4-directionally (horizontal or vertical.) You may assume all four edges of the grid are surrou...

在一个 N × N 的方形网格中，每个单元格有两种状态：空（0）或者阻塞（1）。一条从左上角到右下角、长度为 k 的畅通路径，由满足下述条件的单元格 C_1, C_2, ..., C_k 组成： 相邻单元格 C_i 和 C_{i+1} 在八个方向之一上连通（此时，C_i 和 C_{i+1} 不同且共享边或角） C_1 位于 (0, 0)（即，值为 grid[0][0]）...

Given two strings s1, s2, find the lowest ASCII sum of deleted characters to make two strings equal.Example 1:Input: s1 = "sea", s2 = "eat"Output: 231Explanation: Deleting "s" from "sea" adds the...

给定一个二叉树，它的每个结点都存放一个0-9的数字，每条从根到叶子节点的路径都代表一个数字。例如，从根到叶子节点路径1->2->3代表数字123。计算从根到叶子节点生成的所有数字之和。说明:叶子节点是指没有子节点的节点。示例 1:输入: [1,2,3] 1 / \ 2 3输出: 25解释:从根到叶子节点路径 1->2 ...

给定一个非空二叉树，返回其最大路径和。本题中，路径被定义为一条从树中任意节点出发，达到任意节点的序列。该路径至少包含一个节点，且不一定经过根节点。示例 1:输入: [1,2,3] 1 / \ 2 3输出: 6示例2:输入: [-10,9,20,null,null,15,7] -10 / \ 9 20 ...

给定一个完美二叉树，其所有叶子节点都在同一层，每个父节点都有两个子节点。二叉树定义如下：struct Node { int val; Node *left; Node *right; Node *next;}填充它的每个 next 指针，让这个指针指向其下一个右侧节点。如果找不到下一个右侧节点，则将 next 指针设置为NULL。初始状态下，所有next 指针都被...

给定一个二叉树，原地将它展开为链表。例如，给定二叉树 1 / \ 2 5 / \ \3 4 6将其展开为：1 \ 2 \ 3 \ 4 \ 5 \ 6AC：/** * Definition for a binary tree...

给定一个二叉树和一个目标和，找到所有从根节点到叶子节点路径总和等于给定目标和的路径。说明:叶子节点是指没有子节点的节点。示例:给定如下二叉树，以及目标和sum = 22， 5 / \ 4 8 / / \ 11 13 4 / \ ...

假设你正在爬楼梯。需要n阶你才能到达楼顶。每次你可以爬 1 或 2 个台阶。你有多少种不同的方法可以爬到楼顶呢？注意：给定n是一个正整数。示例 1：输入： 2输出： 2解释： 有两种方法可以爬到楼顶。1. 1 阶 + 1 阶2. 2 阶示例 2：输入： 3输出： 3解释： 有三种方法可以爬到楼顶。1. 1 阶 + 1 阶 + 1 阶2. ...