题解真的是太神奇了2333 用离线和树状数组(为什么感觉和HH的项链是的,什么鬼),比较巧妙的是他把整个数列分成几段.用一个vector来记录每个数出现的位置.一共就是data[a[i]][sz]---data[a[i]][sz-a[i]],data[a[i]][sz-a[i]]----data[a[i]][sz-a[i]-1],0----data[a[i]][sz-a[i]-1],第一个区间的数是1,第二个区间是-1,第三个是0,这样区间加减的话就直接出来了是不是成立一共有a[i]个a[i]而…

D. Little Elephant and Array time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output The Little Elephant loves playing with arrays. He has array a, consisting of n positive integers, indexed from…

221D - Little Elephant and Array 思路: 莫队: 代码: #include <cmath> #include <cstdio> #include <cstring> #include <iostream> #include <algorithm> using namespace std; #define maxn 100005 struct QueryType { int l,r,id; }; struct Que…

Little Elephant and Array Time Limit: 4000ms Memory Limit: 262144KB This problem will be judged on CodeForces. Original ID: 221D64-bit integer IO format: %I64d      Java class name: (Any) The Little Elephant loves playing with arrays. He has array a,…

B. Little Elephant and Array time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output The Little Elephant loves playing with arrays. He has array a, consisting of n positive integers, indexed from…

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…

二次联通门 : Codeforces 221d D. Little Elephant and Array /* Codeforces 221d D. Little Elephant and Array 题意 : 询问一段区间中出现次数等于自身的数的个数 正解是dp 莫队水过, 作为我莫队的入门题 myj的思路 66 把所有需查询的区间排序 当前查询区间的答案为上一个区间的答案通过多次的区间移动得出 */ #include <algorithm> #include <cstdio>…

更好的阅读体验 Portal Portal1: Codeforces Portal2: Luogu Description The Little Elephant loves playing with arrays. He has array \(a\), consisting of \(n\) positive integers, indexed from \(1\) to \(n\). Let's denote the number with index \(i\) as \(a_i\).…

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…

This problem can be solve in simpler O(NsqrtN) solution, but I will describe O(NlogN) one. We will solve this problem in offline. For each x (0 ≤ x < n) we should keep all the queries that end in x. Iterate that x from 0 to n - 1. Also we need to kee…