fujch3的博客

【题目描述】偶数 个人站成一个圆，总人数为 num_people 。每个人与除自己外的一个人握手，所以总共会有 num_people / 2 次握手。将握手的人之间连线，请你返回连线不会相交的握手方案数。由于结果可能会很大，请你返回答案 模 10^9+7 后的结果。【示例】输入：num_people = 2输出：1输入：num_people = 4输出：2解释：总共有两种方案，第一种方案是 [(1,2),(3,4)] ，第二种方案是 [(2,3),(4,1)] 。输入：num

【题目描述】给定一个 没有重复 数字的序列，返回其所有可能的全排列。【示例】输入: [1,2,3]输出:[[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]【代码】class Solution {public: void perm(vector<vector<int> > &res, vector<int>& nums, int start, int end)

【题目描述】给定一组不含重复元素的整数数组 nums，返回该数组所有可能的子集（幂集）。说明：解集不能包含重复的子集。【示例】输入: nums = [1,2,3]输出:[[3],[1],[2],[1,2,3],[1,3],[2,3],[1,2],[]]【解题思路】这道题利用递归，每次固定一个数，然后保存，再继续遍历下去【代码】class Solution {public: void DFS(vector<vector<int>>

【题目描述】给定一组非负整数，重新排列它们的顺序使之组成一个最大的整数。【示例】输入: [10,2]输出: 210输入: [3,30,34,5,9]输出: 9534330【解题思路】自定义一种排序比较方法，就是判断ab>ba注意如果数组全是0，输出为“0”【代码】class Solution {public: static bool comp(const string a, const string b) { string sum1 =

【题目描述】给定一个非空且只包含非负数的整数数组 nums, 数组的度的定义是指数组里任一元素出现频数的最大值。你的任务是找到与 nums 拥有相同大小的度的最短连续子数组，返回其长度。【示例】输入: [1, 2, 2, 3, 1]输出: 2解释:输入数组的度是2，因为元素1和2的出现频数最大，均为2.连续子数组里面拥有相同度的有如下所示:[1, 2, 2, 3, 1], [1, 2, 2, 3], [2, 2, 3, 1], [1, 2, 2], [2, 2, 3], [2, 2]

【题目描述】给定四个包含整数的数组列表 A , B , C , D ,计算有多少个元组 (i, j, k, l) ，使得 A[i] + B[j] + C[k] + D[l] = 0。为了使问题简单化，所有的 A, B, C, D 具有相同的长度 N，且 0 ≤ N ≤ 500 。所有整数的范围在 -228 到 228 - 1 之间，最终结果不会超过 231 - 1 。【示例】输入:A = [ 1, 2]B = [-2,-1]C = [-1, 2]D = [ 0, 2]输出:2解释

【题目描述】给定一个包含 n 个整数的数组 nums 和一个目标值 target，判断 nums 中是否存在四个元素 a，b，c 和 d ，使得 a + b + c + d 的值与 target 相等？找出所有满足条件且不重复的四元组。注意：答案中不可以包含重复的四元组。【示例】给定数组 nums = [1, 0, -1, 0, -2, 2]，和 target = 0。满足要求的四元组集合为：[[-1, 0, 0, 1],[-2, -1, 1, 2],[-2, 0, 0, 2]

【题目描述】给你一个包含 n 个整数的数组 nums，判断 nums 中是否存在三个元素 a，b，c ，使得 a + b + c = 0 ？请你找出所有满足条件且不重复的三元组。注意：答案中不可以包含重复的三元组。【示例】给定数组 nums = [-1, 0, 1, 2, -1, -4]，满足要求的三元组集合为：[[-1, 0, 1],[-1, -1, 2]]【解题思路】1.暴力解法，就是我们用三个循环嵌套，然后找出和为0的三个数，但是这种情况下很耗时，时间复杂度为O(n^3)

Next Greater Element II

Given two arrays, write a function to compute their intersection.

Given two arrays, write a function to compute their intersection.

题目来源【Leetcode】 Given a binary array, find the maximum number of consecutive 1s in this array. Example 1: Input: [1,1,0,1,1,1] Output: 3 Explanation: The first two digits or the last thr

题目来源【Leetcode】 In MATLAB, there is a very useful function called ‘reshape’, which can reshape a matrix into a new one with different size but keep its original data. You’re given a matrix repres

题目来源【Leetcode】 Given an array of 2n integers, your task is to group these integers into n pairs of integer, say (a1, b1), (a2, b2), …, (an, bn) which makes sum of min(ai, bi) for all i from 1 to n as

Minesweeper

Friend Circles

Minimum Depth of Binary Tree

Binary Tree Paths

Symmetric Tree

Search a 2D Matrix II

Maximum Subarray

LeetCode

LeetCode

Next Greater Element I解题代码

Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times.

LeetCode题目来源 Find the kth largest element in an unsorted array. Note that it is the kth largest element in the sorted order, not the kth distinct element. For example, Given [3,2,1,5,6,4] and k

DFS

DFS

1001. 会议安排

1002. 等价二叉树

1003. 相连的1

题目来源【Leetcode】 Given an array of integers where 1 ≤ a[i] ≤ n (n = size of array), some elements appear twice and others appear once. Find all the elements of [1, n] inclusive that do not appear

题目来源【Leetcode】 Given an array nums, write a function to move all 0’s to the end of it while maintaining the relative order of the non-zero elements. For example, given nums = [0, 1, 0, 3, 12], a

题目来源【Leetcode】 Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number. The function twoSum should return indices

题目来源【Leetcode】 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 yo

题目来源【Leetcode】 Given an integer array, find three numbers whose product is maximum and output the maximum product. Example 1: Input: [1,2,3] Output: 6 Example 2: Input: [1,2,3,4]

题目来源【Leetcode】 Given an array of integers, find if the array contains any duplicates. Your function should return true if any value appears at least twice in the array, and it should return false

题目来源【Leetcode】 Given an array containing n distinct numbers taken from 0, 1, 2, …, n, find the one that is missing from the array. For example, Given nums = [0, 1, 3] return 2. Note:

题目来源【Leetcode】 Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order. You may assume no duplic

题目来源【Leetcode】 Given a non-negative integer represented as a non-empty array of digits, plus one to the integer. You may assume the integer do not contain any leading zero, except the number