[CF886E]Maximum Element 题意:小P有一个1-n的序列,他想找到整个序列中最大值的出现位置,但是他觉得O(n)扫一遍太慢了,所以它采用了如下方法: 1.逐个遍历每个元素,如果这个元素比当前记录的最大值大,则令最大值等于当前元素,并令cnt=02.如果这个元素没有当前元素大,则cnt++.3.如果cnt=k,则返回当前最大值 现在小P想知道有多少种序列在使用他的方法时会得到错误的答案.为了简化问题,我们假定原序列是一个1-n的排列.即我们要求的是:给定n和k,有多少个1-n的…

题目 考虑正难则反,答案即为\(n!-\text{返回值为n的排列数}\) 一个排列的返回值为\(n\),当且仅当在\(n\)出现之前没有一个数后面有连续\(k\)个小于它的数 设\(f_i\)表示\(1\)到\(i\)的排列中,没有任何一个数后面有连续\(k\)个小于它的数 枚举\(i\)的位置,则有 \[f_i=\sum_{j=1}^kA_{i-1}^{j-1}f_{i-j}\] 即把\(i\)放在倒数第\(j\)个位置,从\(1\)到\(i-1\)中选\(j-1\)个数排列在\(i\)后面…

[CF888E]Maximum Subsequence(meet in the middle) 题面 CF 洛谷 题解 把所有数分一下,然后\(meet\ in\ the\ middle\)做就好了. 一侧的数正序,另一侧倒序,这样子指针单调就做完了. #include<iostream> #include<cstdio> #include<cstdlib> #include<cstring> #include<cmath> #include&l…

[CF888E]Maximum Subsequence 题意:给你一个序列{ai},让你从中选出一个子序列,使得序列和%m最大. n<=35,m<=10^9 题解:不小心瞟了一眼tag就一下子知道怎么做了,吓得我赶紧把tag屏蔽了. 我们将原序列拆成两半,每一部分都暴力搜索出所有的子序列之和,用set存起来.然后枚举前一半的所有子序列和,设其为x,则使得总和%m最大的右半部分子序列和一定是所有<m-x的数中最大的那个,在set里找一下前驱就行了. #include <cstdio&…

题目: Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [−2,1,−3,4,−1,2,1,−5,4],the contiguous subarray [4,−1,2,1] has the largest sum = 6. click to show more practice.…

1.   Maximum Subarray (#53) Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [-2, 1, -3, 4, -1, 2, 1, -5, 4], the contiguous subarray [4, -1, 2, 1] has the largest s…

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…

Maximum Gap Given an unsorted array, find the maximum difference between the successive elements in its sorted form. Try to solve it in linear time/space. Return 0 if the array contains less than 2 elements. You may assume all elements in the array a…

Maximum Subarray Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [−2,1,−3,4,−1,2,1,−5,4],the contiguous subarray [4,−1,2,1] has the largest sum = 6. More practice:…

Given an unsorted array, find the maximum difference between the successive elements in its sorted form. Try to solve it in linear time/space. Return 0 if the array contains less than 2 elements. You may assume all elements in the array are non-negat…