D. Swaps in Permutation 题目连接: http://www.codeforces.com/contest/691/problem/D Description You are given a permutation of the numbers 1, 2, ..., n and m pairs of positions (aj, bj). At each step you can choose a pair from the given positions and swap…

题目链接:http://codeforces.com/problemset/problem/691/D 给你n个数,各不相同,范围是1到n.然后是m行数a和b,表示下标为a的数和下标为b的数可以交换无数次.问你最后字典序最大的数列是什么. 将下面的a和b用并查集联系起来存到祖节点对应的数组中,然后从大到小排序数组,最后依次按照父节点的数组中的顺序输出. 也可以用dfs的方法解(略麻烦),形成一个环路的就在一个数组中... //并查集 #include <bits/stdc++.h> using…

题目链接:http://codeforces.com/contest/691/problem/D 题意: 题目给出一段序列,和m条关系,你可以无限次互相交换这m条关系 ,问这条序列字典序最大可以为多少 思路: 并查集维护这m条关系,用个vector存一下当前点所能到达的点,拍下序大的优先,输出的时候输出当前点所能找到的最大的数,已输出的标记下就好了. 实现代码: #include<bits/stdc++.h> using namespace std; ; int f[M],vis[M],a[M…

题目链接 分析:一些边把各个节点连接成了一颗颗树.因为每棵树上的边可以走任意次,所以不难想出要字典序最大,就是每棵树中数字大的放在树中节点编号比较小的位置. 我用了极为暴力的方法,先dfs每棵树,再用了优先队列.我估计最大复杂度约在,理论上应该跑不过.因为再cf上做题,看见5s时限,强行上了.很侥幸,在4秒的时候过了= =. /*****************************************************/ //#pragma comment(linker, "/ST…

A - Fashion in Berland 水 // #pragma comment(linker, "/STACK:102c000000,102c000000") #include <iostream> #include <cstdio> #include <cstring> #include <sstream> #include <string> #include <algorithm> #include &…

D. Optimal Number Permutation 题目连接: http://www.codeforces.com/contest/622/problem/D Description You have array a that contains all integers from 1 to n twice. You can arbitrary permute any numbers in a. Let number i be in positions xi, yi (xi < yi) i…

C. Exponential notation 题目连接: http://www.codeforces.com/contest/691/problem/C Description You are given a positive decimal number x. Your task is to convert it to the "simple exponential notation". Let x = a·10b, where 1 ≤ a < 10, then in gen…

B. s-palindrome 题目连接: http://www.codeforces.com/contest/691/problem/B Description Let's call a string "s-palindrome" if it is symmetric about the middle of the string. For example, the string "oHo" is "s-palindrome", but the…

A. Fashion in Berland 题目连接: http://www.codeforces.com/contest/691/problem/A Description According to rules of the Berland fashion, a jacket should be fastened by all the buttons except only one, but not necessarily it should be the last one. Also if…

题目链接:http://codeforces.com/problemset/problem/691/F 题目大意:给定n个数,再给m个询问,每个询问给一个p,求n个数中有多少对数的乘积≥p 数据范围:2≤n≤10^6, 1≤ai≤3*10^6,1≤m≤10^6, 1≤p≤3*10^6 解题思路:比赛的时候比较naive的思路是把n中的数字排序去了重之后,对于每个p,最多枚举√p步,就能得到答案.而这个naive的思路是O(p√p)的,结果T了. 后来百思不得其解,去看了官方的解答.感觉是一种很有…