题目概述: Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times. You may assume that the array is non-empty and the majority element always exist in the array. 解题思路: 这个题解法很多,官方就给了七种…

Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times. You may assume that the array is non-empty and the majority element always exist in the array. 思路: 找主要元素,用major记录主要字母,n记录ma…

今天遇到的题都挺难的,不容易有会做的. 下面是代码,等明天看看Discuss里面有没有简单的方法~ Majority Element My Submissions Question Total Accepted: 79833 Total Submissions: 208075 Difficulty: Easy Given an array of size n, find the majority element. The majority element is the element that…

题目: 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: 首先,我们来看一下怎样求众数,也就是元素出现大于⌊ n/2 ⌋的数. 我们注意到这样一个现象: 在任何数组中,出现次数大于该数组长度一半的值只能有一个. 通过数学知识,我们可以证明它的正确…

题目概述: Given an array and a value, remove all instances of that value in place and return the new length. The order of elements can be changed. It doesn't matter what you leave beyond the new length. 解题思路: 说实话,这道题目的描述很是不清楚,以至于我觉得很多人会觉得过oj的话只需要统计有多少个不是…

Given an array and a value, remove all instances of that value in place and return the new length. The order of elements can be changed. It doesn't matter what you leave beyond the new length. 思路: s记录下一个判断位置, e记录结束位置,把前面的待排除元素与后面要保留的元素互换. int removeE…

题目如下: Given an integer array sorted in non-decreasing order, there is exactly one integer in the array that occurs more than 25% of the time. Return that integer. Example 1: Input: arr = [1,2,2,6,6,6,6,7,10] Output: 6 Constraints: 1 <= arr.length <=…

[78]Subsets 给了一个 distinct 的数组,返回它所有的子集. Example: Input: nums = [,,] Output: [ [], [], [], [,,], [,], [,], [,], [] ] 题解:我是直接dfs(backtracking)了,有个小地方写错了(dfs那里),至少调整了十多分钟,下次不要写错了. class Solution { public: vector<vector<int>> subsets(vector<int…

链接:https://leetcode.com/tag/divide-and-conquer/ [4]Median of Two Sorted Arrays [23]Merge k Sorted Lists [53]Maximum Subarray (2019年1月23日, 谷歌tag复习) 最大子段和. 题解: follow up 是divide and conquer If you have figured out the O(n) solution, try coding another…

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…