CodeForces 86 D Powerful array 莫队】的更多相关文章

Powerful array 题意:求区间[l, r] 内的数的出现次数的平方 * 该数字. 题解:莫队离线操作, 然后加减位置的时候直接修改答案就好了. 这个题目中发现了一个很神奇的事情,本来数组开1e6大小就直接过了4100+ms, 想测试一下inline,顺手把空间砍成了刚好够用,然后跑的更慢了 4700+ms,删了inline之后T了,到现在也不知道发生了啥. 如果有大牛路过希望帮我看下,  CF run id  38822420(4100+) 38822607(4700+)388226…
题目链接:http://codeforces.com/problemset/problem/86/D D. Powerful array time limit per test 5 seconds memory limit per test 256 megabytes input standard input output standard output An array of positive integers a1, a2, ..., an is given. Let us consider…
传送门:https://codeforces.com/contest/86/problem/D 题意: 给你n个数,m次询问,每次询问问你在区间l,r内每个数字出现的次数的平方于当前这个数的乘积的和 题解: 莫队算法 思路: 根据平方和公式我们知道 \[ (a+1)^2=a^2+2a+1 \] 于是在记录每一次询问的答案时 add操作就是加上这个数的贡献 del操作就是减去这个数的贡献 每个数多出一次或者减少一次的对答案贡献就是 \[ a_i*(cnt[a[i]]*2+1) \] 代码: /**…
题目链接: D. Powerful array time limit per test 5 seconds memory limit per test 256 megabytes input standard input output standard output An array of positive integers a1, a2, ..., an is given. Let us consider its arbitrary subarray al, al + 1..., ar, wh…
题目链接:http://codeforces.com/problemset/problem/86/D 题目大意:给定一个数组,每次询问一个区间[l,r],设cnt[i]为数字i在该区间内的出现次数,求该区间内所有的cnt[i]^2*i. 解题思路:莫队模板题,改一下add,remove就好了. #include<iostream> #include<algorithm> #include<cmath> using namespace std; typedef long…
题意:查询的是区间内每个数出现次数的平方×该数值的和. 分析:虽然是道莫队裸体,但是姿势不对就会超时.答案可能爆int,所以要开long long 存答案.一开始的维护操作,我先在res里减掉了a[pos]*cnt[a[pos]]*cnt[a[pos]],将cnt[a[pos]]+1,再将乘积加回.其实根据数学原理,K^2和(K+1)^2差值是2K+1,那么其实每次更新时只要加上或减去a[pos]*(2*cnt[pos]+1)即可,这样更高效. #include<bits/stdc++.h>…
莫队算法就是优化的暴力算法.莫队算法是要把询问先按左端点属于的块排序,再按右端点排序.只是预先知道了所有的询问.可以合理的组织计算每个询问的顺序以此来降低复杂度. D. Powerful array 典型的莫队算法题 #include <iostream> #include <cstdio> #include <cstring> #include <cmath> #include <algorithm> #include <string&g…
题目链接:点击传送 D. Powerful array time limit per test 5 seconds memory limit per test 256 megabytes input standard input output standard output An array of positive integers a1, a2, ..., an is given. Let us consider its arbitrary subarray al, al + 1..., ar…
题意:定义K[x]为元素x在区间[l,r]内出现的次数,那么它的贡献为K[x]*K[x]*x 给定一个序列,以及一些区间询问,求每个区间的贡献 算是莫队算法膜版题,不带修改的 Code #include <cstdio> #include <algorithm> #include <cmath> #define N 200010 #define ll long long using namespace std; int n,m,A[N],bl[N],k[N*5]; ll…
传送门:https://codeforces.com/problemset/problem/220/B 题意: 给你n个数,m次询问,每次询问问你在区间l,r内有多少个数满足其值为其出现的次数 题解: 莫队算法 思路:每次区间向外扩的更新的过程中,检查该位置的数ai的出现次数是否已经达到ai或ai+1,以判断是否要更新结果.同理,区间收缩的时候判断ai出现次数是否达到ai或ai-1. 因为数据范围为1e9,所以需要离散化,方便记录每种数出现的次数 代码: /** * ┏┓ ┏┓ * ┏┛┗━━━…
题意:N个数,M个查询,求[Li,Ri]区间内出现次数等于其数值大小的数的个数. 分析:用莫队处理离线问题是一种解决方案.但ai的范围可达到1e9,所以需要离散化预处理.每次区间向外扩的更新的过程中,检查该位置的数ai的出现次数是否已经达到ai或ai+1,以判断是否要更新结果.同理,区间收缩的时候判断ai出现次数是否达到ai或ai-1. 另一种更高效的方法是使用树状数组离线处理查询.用一个vector数组维护每个ai以此出现的位置.显然ai>N的数不会对结果做出贡献,所以数组开1e5就足够了.树…
F. Machine Learning time limit per test 4 seconds memory limit per test 512 megabytes input standard input output standard output You come home and fell some unpleasant smell. Where is it coming from? You are given an array a. You have to answer the…
An array of positive integers a1, a2, ..., an is given. Let us consider its arbitrary subarray al, al + 1..., ar, where 1 ≤ l ≤ r ≤ n. For every positive integer s denote by Ks the number of occurrences of s into the subarray. We call the power of th…
转换成前缀和, 预处理一下然后莫队. #include<bits/stdc++.h> #define LL long long #define fi first #define se second #define mk make_pair #define PLL pair<LL, LL> #define PLI pair<LL, int> #define PII pair<int, int> #define SZ(x) ((int)x.size()) #de…
题目描述 On a plane are nn points ( x_{i}xi​ , y_{i}yi​ ) with integer coordinates between 00 and 10^{6}106 . The distance between the two points with numbers aa and bb is said to be the following value:  (the distance calculated by such formula is calle…
Tree and Queries 题意:有一颗以1号节点为根的树,每一个节点有一个自己的颜色,求出节点v的子数上颜色出现次数>=k的颜色种类. 题解:使用莫队处理这个问题,将树转变成DFS序区间,然后就是开一个数据记录下出现次数为k次的颜色数目,查询的时候直接返回这个数组中的对应的值就行了. 注意的就是记得将节点的颜色传递给dfs序对应位置的颜色. 这个忘记了找了好久的bug. 代码: #include<bits/stdc++.h> using namespace std; #defin…
You come home and fell some unpleasant smell. Where is it coming from? You are given an array a. You have to answer the following queries: You are given two integers l and r. Let ci be the number of occurrences of i inal: r, where al: r is the subarr…
题目链接 Powerful array 给你n个数,m次询问,Ks为区间内s的数目,求区间[L,R]之间所有Ks*Ks*s的和. $1<=n,m<=200000,   1<=s<=10^{6}$ 考虑莫队算法 把区间排序,然后让l和r分别询问即可. 根据排序的方式,l指针和r指针移动次数和大概是$n\sqrt{n}$ 级别的. #include <bits/stdc++.h> using namespace std; #define rep(i, a, b) for (…
D. Powerful array time limit per test 5 seconds memory limit per test 256 megabytes input standard input output standard output An array of positive integers a1, a2, ..., an is given. Let us consider its arbitrary subarray al, al + 1..., ar, where 1 …
题目描述: Problem Description An array of positive integers a1, a2, ..., an is given. Let us consider its arbitrary subarray al, al + 1..., ar, where 1 ≤ l ≤ r ≤ n. For every positive integer s denote by Ks the number of occurrences of s into the subarra…
An array of positive integers a1, a2, ..., an is given. Let us consider its arbitrary subarray al, al + 1..., ar, where 1 ≤ l ≤ r ≤ n. For every positive integer s denote by Ks the number of occurrences of s into the subarray. We call the power of th…
D. Powerful array time limit per test 5 seconds memory limit per test 256 megabytes input standard input output standard output An array of positive integers a1, a2, ..., an is given. Let us consider its arbitrary subarray al, al + 1..., ar, where 1 …
D. Powerful array time limit per test seconds memory limit per test megabytes input standard input output standard output An array of positive integers a1, a2, ..., an ..., ar,  ≤ l ≤ r ≤ n. For every positive integer s denote by Ks the number of occ…
vjudge上莫队专题 真的是要吐槽自己(自己的莫队手残写了2个bug) s=sqrt(n) 是元素的个数而不是询问的个数(之所以是sqrt(n)使得左端点每个块左端点的范围嘴都是sqrt(n)) 在重载<是将q[i].l/s<q2[i].l/s 写成q1[i].l<s<q2[i].l<s 导致一下午都在调bug疯了 Sona 比小Z的袜子简单,直接维护区间频度的^3 需要离散化(离散化化的标号应提前准备好,如果用时在二分查找会增加复杂度) 还有比较坑的一点是多case,但样…
The Little Elephant loves playing with arrays. He has array a, consisting of npositive integers, indexed from 1 to n. Let's denote the number with index i as ai. Additionally the Little Elephant has m queries to the array, each query is characterised…
Description An array of positive integers a1, a2, ..., an is given. Let us consider its arbitrary subarray al, al + 1..., ar, where 1 ≤ l ≤ r ≤ n. For every positive integer s denote by Ks the number of occurrences of s into the subarray. We call the…
E. XOR and Favorite Number 题目连接: http://www.codeforces.com/contest/617/problem/E Descriptionww.co Bob has a favorite number k and ai of length n. Now he asks you to answer m queries. Each query is given by a pair li and ri and asks you to count the n…
任意门:http://codeforces.com/problemset/problem/617/E E. XOR and Favorite Number time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output Bob has a favorite number k and ai of length n. Now he asks yo…
E. XOR and Favorite Number time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output Bob has a favorite number k and ai of length n. Now he asks you to answer m queries. Each query is given by a pai…
题目链接:http://codeforces.com/problemset/problem/617/E E. XOR and Favorite Number time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output Bob has a favorite number k and ai of length n. Now he asks y…