Leetcode上面有这么一道难度为easy的算法题:找出一个长度为n的数组中,重复次数超过一半的数,假设这样的数一定存在.O(n2)和O(nlog(n))(二叉树插入)的算法比较直观.Boyer–Moore majority vote algorithm在1980年提出,用O(1)空间和O(n)时间解决了这个问题.这个算法的思路:由于重复频率超过 floor(n/2)的数字只有一个,等价于与其余数字出现频率的差大于零.当遍历整个数组时,使用变量candidate记录当前重复次数最多的数,cou…

题外话 最近有些网友来信问我博客怎么不更新了,是不是不刷题了,真是惭愧啊,题还是在刷的,不过刷题的频率没以前高了,看完<算法导论>后感觉网上很多讨论的题目其实在导论中都已经有非常好的算法以及数学证明,只是照搬的话好像意义也不是很大,希望找到些有代表性的题目在更新,另外希望能接着前面的<穷举递归和回溯算法终结篇>一系列如动态规划.贪心算法类的终结篇,在梳理自己知识结构的同时也能够帮助读者们更系统的学习算法思想.好了话不多说,进入正题. 问题描述 给定一个数组A[n], 定义数组的主元…

题目: 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. 题解:运用多数投票算法的思路来解:从头到尾遍历数…

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. 需要注意的是:这道题只是要找出多数元素,已经默认存在多数…

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. Credits:Special thanks to @t…

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. 给定一个数组,求其中权制最大的元素,(该元素出现超过了一…

在一个数组中找到主要的元素,也就是出现次数大于数组长度一半的元素.容易想到的方式就是计数,出现次数最多的就是majority element,其次就是排序,中间的就是majority element.但是还有两种更有意思的实现方式时间效率O(n),空间效率O(1):1.Moore voting algorithm 投票算法,因为符合要求的majority element总是存在的,所以首先置计数器count=1,并选择数组的第一个元素作为candidate,往后遍历并计数,与candidate相…

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. Credits:Special thanks to @t…

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. 题目标签:Array 忘记说了,特地回来补充,今天看完<…

题目来源: 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. Credits:Special thanks…