再见二丁目

C/C++获取大型文件的大小（体积）

问题Given an integer array, find three numbers whose product is maximum and output the maximum product.Example 1:Input: [1,2,3]Output: 6Example 2:Input: [1,2,3,4]Output: 24Note: * The length of the gi

问题You’re now a baseball game point recorder.Given a list of strings, each string can be one of the 4 following types:Integer (one round's score): Directly represents the number of points you get in thi

问题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 su

问题Given a non-empty array of non-negative integers nums, the degree of this array is defined as the maximum frequency of any one of its elements.Your task is to find the smallest possible length o

720. Longest Word in DictionaryGiven a list of strings words representing an English Dictionary, find the longest word in words that can be built one character at a time by other words in words. If

问题Given a list of sorted characters letters containing only lowercase letters, and given a target letter target, find the smallest element in the list that is larger than the given target.Letters

问题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

竞赛问题Given two integers L and R, find the count of numbers in the range [L, R] (inclusive) having a prime number of set bits in their binary representation.(Recall that the number of set bits an in

问题Median is the middle value in an ordered integer list. If the size of the list is even, there is no middle value. So the median is the mean of the two middle value.Examples: [2,3,4] , the medi

一、问题Given a string, find the length of the longest substring without repeating characters.Examples:Given “abcabcbb”, the answer is “abc”, which the length is 3.Given “bbbbb”, the answer is “b”

问题Write a function that takes a string as input and returns the string reversed.Example:Given s = “hello”, return “olleh”.代码class Solution {public: string reverseString(string s) { //方法一：

问题Given a linked list, determine if it has a cycle in it.Follow up:Can you solve it without using extra space?思考此题初看简单，实则容易走歪。使用 哈希表 unordered_set 来实现的话，就是将指针存进去，每次存之前看set里有没有这个指针，有则说明有cycle。时间复杂度和空间

问题 :MediumGiven 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 nodes with keys less than the node’s key.

一个Class对象需要占用的内存空间：*非静态成员变量总合。*加上编译器为了CPU计算，作出的数据对齐处理。*加上为了支持虚函数，产生的额外负担。

堆 & 栈 的详细对比

LeetCode 1. Two Sun使用unordered_map。

问题Given a string which consists of lowercase or uppercase letters, find the length of the longest palindromes that can be built with those letters.This is case sensitive, for example “Aa” is not consid

问题 easyGiven a binary search tree with non-negative values, find the minimum absolute difference between values of any two nodes.Example:Input: 1 \ 3 / 2Output:1Explanation:The mini

问题 easyGiven a Binary Search Tree and a target number, return true if there exist two elements in the BST such that their sum is equal to the given target.Example 1:Input: 5 / \ 3 6 / \

问题You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return

问题Given a linked list, remove the nth node from the end of list and return its head.For example,Given linked list: 1->2->3->4->5, and n = 2.After removing the second node from the end, the linked list

问题Given a linked list, swap every two adjacent nodes and return its head.For example, Given 1->2->3->4, you should return the list as 2->1->4->3.Your algorithm should use only constant space. You may

问题:You are given an n x n 2D matrix representing an image.Rotate the image by 90 degrees (clockwise).

一、问题Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.二、代码/** * Definition for singly-linked lis