D. Sum of Medians time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output In one well-known algorithm of finding the k-th order statistics we should divide all elements into groups of five consecu…

传送门 D. Sum of Medians time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output In one well-known algorithm of finding the k-th order statistics we should divide all elements into groups of five con…

题目链接: Sum of Medians Time Limit:3000MSMemory Limit:262144KB 问题描述 In one well-known algorithm of finding the k-th order statistics we should divide all elements into groups of five consecutive elements and find the median of each five. A median is cal…

D. Sum of Medians time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output In one well-known algorithm of finding the k-th order statistics we should divide all elements into groups of five consecu…

题目链接:Codeforces 85D - Sum of Medians 题目大意:N个操作,add x:向集合中加入x:del x:删除集合中的x:sum:将集合排序后,将集合中全部下标i % 5 = 3的元素累加求和. 解题思路:线段树单点更新,每一个点维护5个值.分别表示从该段区间中i % 5 = t的和.然后两端区间合并时仅仅须要依据左孩子中元素的个数合并.所以有一个c表示区间上元素的个数. 由于有同样的数.所以要离线操做,将全部的数映射成位置,可是对于del则不须要映射,由于集合中肯定…

D. Sum of Medians Time Limit: 1 Sec  Memory Limit: 256 MB 题目连接 http://codeforces.com/problemset/problem/85/D Description In one well-known algorithm of finding the k-th order statistics we should divide all elements into groups of five consecutive el…

D. Sum of Medians time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output In one well-known algorithm of finding the k-th order statistics we should divide all elements into groups of five consecu…

CF85D Sum of Medians 题意翻译 一个集合,初始为空.现有三个操作: 1.add:向集合里加入数x,保证加入前集合中没有数x: 2.del:从集合中删除数x,保证删除前集合中有x: 3.sum:询问将集合里的数从小到大排序后,求下标i模5余3的数的和. 现有n次操作,对于每个查询操作,输出答案 题解Here! 一开始感觉好不可做啊... 然后发现,线段树好像可以搞一搞. 线段树每个节点维护$5$个值,即区间中所有$\text{下标}\mod5$后结果相同的位置的值的和. 即:在…

传送门 题目 In one well-known algorithm of finding the k-th order statistics we should divide all elements into groups of five consecutive elements and find the median of each five. A median is called the middle element of a sorted array (it's the third l…

Sum of Medians time limit per test 3 seconds memory limit per test 256 megabytes In one well-known algorithm of finding the k-th order statistics we should divide all elements into groups of five consecutive elements and find the median of each five.…

Sum of Medians 题解: 对于这个题目,先想到是建立5棵Splay,然后每次更新把后面一段区间的树切下来,然后再转圈圈把切下来的树和别的树合并. 但是感觉写起来太麻烦就放弃了. 建立5棵线段树. 然后 seg[rt][i]代表的是只考虑当前所管辖的区间中的情况下, 下标对5取余之后为 i 的那些值的和. 最重要的一点是更新. ; i < ; ++i) seg[i][rt] = seg[i][rt<<] + seg[((i-sz[rt<<]%)+)%][rt<…

http://codeforces.com/problemset/problem/85/D 题意: 给你N(0<N<1e5)次操作,每次操作有3种方式, 1.向集合里加一个数a(0<a<1e9)(增加数a之前的集合一定不存在a) 2.向集合里删一个数a(0<a<1e9)(删除数a之前的集合一定存在a) 3.将下标i%5==3的数相加,计算总和并相加. 分析: 先离散,然后线段树,sum[i]用来标识前i项有几个数,ans[rt][i]表示以rt为根的子树中第i大数的和…

题目链接:http://codeforces.com/contest/85/problem/D 做法果然男默女泪啊..... 大概就是直接开了一个$vector$每次插入删除都用自带的$insert$和$erase$,然后查询也是暴力搞. 那么为啥么过得很有理有据呢? 1.首先考虑如果没有修改我就能继承上一次的答案... 2.修改我们假设(就是)${O(logn)}$的. 3.每次暴力查询是$5$个数字一步. 4.显然一开始并不是上来就有${100000}$个数字 所以大概复杂度会是${O(n^…

原文出处:http://www.notonlysuccess.com/ (好像现在这个博客已经挂掉了,在网上找到的全部都是转载) 今天在清北学堂听课,听到了一些很令人吃惊的消息.至于这消息具体是啥,等我晚上再说23333 我大概的看了一下所讲内容及实例,果不愧是大牛级别的人,讲的很详细,所以决定转载过来. 对原文作者致以崇高的敬意. 以下是转载内容. [完全版]线段树 很早前写的那篇线段树专辑至今一直是本博客阅读点击量最大的一片文章,当时觉得挺自豪的,还去pku打广告,但是现在我自己都不太好意思…

线段树完全版  ~by NotOnlySuccess 很早前写的那篇线段树专辑至今一直是本博客阅读点击量最大的一片文章,当时觉得挺自豪的,还去pku打广告,但是现在我自己都不太好意思去看那篇文章了,觉得当时的代码风格实在是太丑了,很多线段树的初学者可能就是看着这篇文章来练习的,如果不小心被我培养出了这么糟糕的风格,实在是过意不去,正好过几天又要给集训队讲解线段树,所以决定把这些题目重新写一遍,顺便把近年我接触到的一些新题更新上去~;并且学习了splay等更高级的数据结构后对线段树的体会有更深了一…

转载自:NotOnlySuccess的博客 [完全版]线段树 很早前写的那篇线段树专辑至今一直是本博客阅读点击量最大的一片文章,当时觉得挺自豪的,还去pku打广告,但是现在我自己都不太好意思去看那篇文章了,觉得当时的代码风格实在是太丑了,很多线段树的初学者可能就是看着这篇文章来练习的,如果不小心被我培养出了这么糟糕的风格,实在是过意不去,正好过几天又要给集训队讲解线段树,所以决定把这些题目重新写一遍,顺便把近年我接触到的一些新题更新上去~;并且学习了splay等更高级的数据结构后对线段树的体会有…

载自:NotOnlySuccess的博客 [完全版]线段树 很早前写的那篇线段树专辑至今一直是本博客阅读点击量最大的一片文章,当时觉得挺自豪的,还去pku打广告,但是现在我自己都不太好意思去看那篇文章了,觉得当时的代码风格实在是太丑了,很多线段树的初学者可能就是看着这篇文章来练习的,如果不小心被我培养出了这么糟糕的风格,实在是过意不去,正好过几天又要给集训队讲解线段树,所以决定把这些题目重新写一遍,顺便把近年我接触到的一些新题更新上去~;并且学习了splay等更高级的数据结构后对线段树的体会有更…

原文出处:http://www.notonlysuccess.com/ 今晚上比赛就考到了 排兵布阵啊,难受. [完全版]线段树 很早前写的那篇线段树专辑至今一直是本博客阅读点击量最大的一片文章,当时觉得挺自豪的,还去pku打广告,但是现在我自己都不太好意思去看那篇文章了,觉得当时的代码风格实在是太丑了,很多线段树的初学者可能就是看着这篇文章来练习的,如果不小心被我培养出了这么糟糕的风格,实在是过意不去,正好过几天又要给集训队讲解线段树,所以决定把这些题目重新写一遍,顺便把近年我接触到的一些新题…

比赛链接:https://codeforces.com/contest/1440 A. Buy the String 题解 枚举字符串中 \(0\) 或 \(1\) 的个数即可. 代码 #include <bits/stdc++.h> using namespace std; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int t; cin >> t; while (t--) { int n, c0, c1…

D - Median of Medians Time limit : 2sec / Memory limit : 1024MB Score : 700 pointsProblem Statement We will define the median of a sequence b of length M, as follows:     Let b' be the sequence obtained by sorting b in non-decreasing order. Then, the…

Two Sum 題目連結 官網題目說明: 解法: 從給定的一組值內找出第一組兩數相加剛好等於給定的目標值,暴力解很簡單(只會這樣= =),兩個迴圈,只要找到相加的值就跳出. /// <summary> /// 暴力解O(n) /// </summary> /// <param name="nums"></param> /// <param name="target"></param> /// &…

题目链接:Path Sum II | LeetCode OJ Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum. For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 1 return [ [5,4,11,2],…

题目链接:Path Sum | LeetCode OJ Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum. For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11…

Sum of Consecutive Prime Numbers Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 20050   Accepted: 10989 Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representatio…

题目链接:Sum 嗯--不要在意--我发这篇博客只是为了保存一下杜教筛的板子的-- 你说你不会杜教筛?有一篇博客写的很好,看完应该就会了-- 这道题就是杜教筛板子题,也没什么好讲的-- 下面贴代码(不知道为什么我的常数就是大): #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<cmath> #define File(s) freo…

You are given a binary tree in which each node contains an integer value. Find the number of paths that sum to a given value. The path does not need to start or end at the root or a leaf, but it must go downwards (traveling only from parent nodes to…

Given a non-empty array containing only positive integers, find if the array can be partitioned into two subsets such that the sum of elements in both subsets is equal. Note: Both the array size and each of the array element will not exceed 100. Exam…

Given an array which consists of non-negative integers and an integer m, you can split the array into m non-empty continuous subarrays. Write an algorithm to minimize the largest sum among these m subarrays. Note:Given m satisfies the following const…

Find the sum of all left leaves in a given binary tree. Example: 3 / \ 9 20 / \ 15 7 There are two left leaves in the binary tree, with values 9 and 15 respectively. Return 24. 这道题让我们求一棵二叉树的所有左子叶的和,那么看到这道题我们知道这肯定是考二叉树的遍历问题,那么最简洁的写法肯定是用递归,由于我们只需要累加左子叶…

Given an integer array with all positive numbers and no duplicates, find the number of possible combinations that add up to a positive integer target. Example: nums = [1, 2, 3] target = 4 The possible combination ways are: (1, 1, 1, 1) (1, 1, 2) (1,…