题目标签:HashMap 题目给了我们一个size 为 2N 的int array,其中有 N + 1 个唯一的 数字,让我们找出那个重复的数字. 利用hashset,把每一个数字存入,一旦发现有重复的,就返回这个数字. Java Solution: Runtime: 4 ms, faster than 93.76% Memory Usage: 40.7 MB, less than 65.88% 完成日期:03/11/2019 关键点:hashset class Solution { publi…
在大小为 2N 的数组 A 中有 N+1 个不同的元素,其中有一个元素重复了 N 次. 返回重复了 N 次的那个元素. 示例 1: 输入:[1,2,3,3] 输出:3 示例 2: 输入:[2,1,2,5,3,2] 输出:2 示例 3: 输入:[5,1,5,2,5,3,5,4] 输出:5 提示: 4 <= A.length <= 10000 0 <= A[i] < 10000 A.length 为偶数 class Solution { public: int repeatedNTim…
In a array A of size 2N, there are N+1 unique elements, and exactly one of these elements is repeated N times. Return the element repeated N times. Example 1: Input: [1,2,3,3] Output: 3 Example 2: Input: [2,1,2,5,3,2] Output: 2 Example 3: Input: [5,1…
problem 961. N-Repeated Element in Size 2N Array solution: class Solution { public: int repeatedNTimes(vector<int>& A) { unordered_map<int, int> amap; for(auto a:A) { amap[a]++; } , max_val; for(auto a:amap) { if(a.second>max_num) { max…
905. Sort Array By Parity (Easy)# Given an array A of non-negative integers, return an array consisting of all the even elements of A, followed by all the odd elements of A. You may return any answer array that satisfies this condition. Example 1: In…
作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 字典 日期 题目地址:https://leetcode.com/problems/n-repeated-element-in-size-2n-array/ 题目描述 In a array A of size 2N, there are N+1 unique elements, and exactly one of these elements is…
In a array A of size 2N, there are N+1 unique elements, and exactly one of these elements is repeated N times. Return the element repeated N times. Example 1: Input: [1,2,3,3] Output: 3 Example 2: Input: [2,1,2,5,3,2] Output: 2 Example 3: Input: [5,1…
题目要求 In a array A of size 2N, there are N+1 unique elements, and exactly one of these elements is repeated N times. Return the element repeated N times. 题目分析及思路 题目给出一个长度为2N的数组,其中有N+1个不同元素,有一个元素重复了N次,要求返回该重复N次的元素.可以随机从数组中获得两个元素,如果这两个元素相同,则该元素就是题目所要返回的…
题目如下: In a array A of size 2N, there are N+1 unique elements, and exactly one of these elements is repeated N times. Return the element repeated N times. Example 1: Input: [1,2,3,3] Output: 3 Example 2: Input: [2,1,2,5,3,2] Output: 2 Example 3: Input…
In a array A of size 2N, there are N+1 unique elements, and exactly one of these elements is repeated N times. Return the element repeated N times. Example 1: Input: [1,2,3,3] Output: 3 Example 2: Input: [2,1,2,5,3,2] Output: 2 Example 3: Input: [5,1…
这是悦乐书的第365次更新,第393篇原创 01 看题和准备 今天介绍的是LeetCode算法题中Easy级别的第227题(顺位题号是961).在大小为2N的数组A中,存在N+1个唯一元素,并且这些元素中的一个重复N次. 返回重复N次的元素.例如: 输入:[1,2,3,3] 输出:3 输入:[2,1,2,5,3,2] 输出:2 输入:[5,1,5,2,5,3,5,4] 输出:5 注意: 4 <= A.length <= 10000 0 <= A [i] <10000 A.lengt…
In a array A of size 2N, there are N+1 unique elements, and exactly one of these elements is repeated N times. Return the element repeated N times. Example 1: Input: [1,2,3,3] Output: 3 Example 2: Input: [2,1,2,5,3,2] Output: 2 Example 3: Input: [5,1…
作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 解题方法 方法一:异或 方法二:判断相邻元素是否相等 方法三:二分查找 日期 题目地址:https://leetcode.com/problems/single-element-in-a-sorted-array/description/ 题目描述 Given a sorted array consisting of only integers where every…
题目如下: 解题思路:题目要求时间复杂度是O(logN),可以尝试使用二分查找法.首先数组是有序的,而且仅有一个元素出现一次,其余均为两次.我们可以先找到数组最中间的元素,记为mid.如果mid和mid-1以及mid+1都不相同,那么mid就是single number.如果mid和mid-1相同,就要分两种情况,a.mid是奇数,single number会出现在mid的右半边:b.mid是偶数,出现在左半边.同理,如果mid和mid+1相同,那么是相反的:a.mid是奇数,出现在左半边:b.…
注意multiset的一个bug: multiset带一个参数的erase函数原型有两种.一是传递一个元素值,如上面例子代码中,这时候删除的是集合中所有值等于输入值的元素,并且返回删除的元素个数:另外一种是传递一个指向某个元素的iterator,这时候删除的就是这个对应的元素,无返回值. https://www.cnblogs.com/lakeone/p/5600494.html 删除的时候一定不能删除指针,只能删除迭代器 leetcode那个题就是在这个地方出错的: Input: [3,2,3…
Given an integer array of size n, find all elements that appear more than ⌊ n/3 ⌋ times. The algorithm should run in linear time and in O(1) space. 思路: [LeetCode 169]Majority Element 的拓展,这回要求的是出现次数超过三分之一次的数字咯,动动我们的大脑思考下,这样的数最多会存在几个呢,当然是2个嘛.因此,接着上一题的方…
636.Kth Largest Element in an Array 1.Problem 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. 题意很简单,找到一个一维数组中的第K大的数并返回.数组中第K大的数也是面试中经常考察的问题.现在就借Leetcode上的这题…
Kth Largest Element in an Array 题解 题目来源:https://leetcode.com/problems/kth-largest-element-in-an-array/description/ Description Find the kth largest element in an unsorted array. Note that it is the kth largest element in the sorted order, not the kth…
传送门 有一个整数数组,请你根据快速排序的思路,找出数组中第K大的数. 给定一个整数数组a,同时给定它的大小n和要找的K(K在1到n之间),请返回第K大的数,保证答案存在. 测试样例: [1,3,5,2,2],5,3 返回:2 note: 注意手写快排的时候: while(i < j) { while(j > i && a[j] > a[left]) j--; while(i < j && a[i] <= a[left]) i++; if(i…
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. Example 1: Input: [3,2,1,5,6,4] and k = 2 Output: 5 Example 2: Input: [3,2,3,1,2,4,5,5,6] and k = 4 Output:…
You are given two arrays (without duplicates) nums1 and nums2 where nums1’s elements are subset of nums2. Find all the next greater numbers for nums1's elements in the corresponding places of nums2. The Next Greater Number of a number x in nums1 is t…
Given a circular array (the next element of the last element is the first element of the array), print the Next Greater Number for every element. The Next Greater Number of a number x is the first greater number to its traversing-order next in the ar…
Given a positive 32-bit integer n, you need to find the smallest 32-bit integer which has exactly the same digits existing in the integer nand is greater in value than n. If no such positive 32-bit integer exists, you need to return -1. Example 1: In…
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 = 2, return 5. Note: You may assume k is always valid, 1 ≤ k ≤ array's…
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 = 2, return 5. 思路: 堆.讲解:二叉堆 class Solution { public: //新插入i结点 其父节点为(i…
一天一道LeetCode系列 (一)题目 Given an array and a value, remove all instances of that value in place and return the new length. Do not allocate extra space for another array, you must do this in place with constant memory. The order of elements can be change…
版权声明: 本文为博主Bravo Yeung(知乎UserName同名)的原创文章,欲转载请先私信获博主允许,转载时请附上网址 http://blog.csdn.net/lzuacm. C#版 - Leetcode 215. Kth Largest Element in an Array-题解 在线提交: https://leetcode.com/problems/kth-largest-element-in-an-array/ Description Find the k th largest…
乘风破浪:LeetCode真题_027_Remove Element 一.前言 这次是从数组中找到一个元素,然后移除该元素的所有结果,并且返回长度. 二.Remove Element 2.1 问题 2.2 分析与解决     这个题和上一题是非常相似的,只不过这次是从数组中找到给定的元素,并且删除该元素,同时返回剩余数组的长度,超过长度的元素不用管,存不存在都可以.于是我们想到了和上次一样的方法,用一个指针指向开始,一个指向结尾,开始的向后移动,如果遇到需要删除的元素,则用最后的元素替代,最后的…
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. Example 1: Input: [3,2,1,5,6,4] and k = 2 Output: 5 Example 2: Input: [3,2,3,1,2,4,5,5,6] and k = 4 Output:…
lc 215 Kth Largest Element in an Array 215 Kth Largest Element in an Array 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]…