太难了,学不会.看了两天都会背了,但是感觉题目稍微变下就不会了.dp还是摸不到路子. 附ac代码: 1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<algorithm> 5 #include<vector> 6 using namespace std; 7 typedef long long ll; 8 ll dp[1<<20][20],an…

状态压缩/Bitmask 在动态规划问题中,我们会遇到需要记录一个节点是否被占用/是否到达过的情况.而对于一个节点数有多个甚至十几个的问题,开一个巨型的[0/1]数组显然不现实.于是就引入了状态压缩,用一个整数的不同二进制位来表示该节点的状态. Description Given a simple graph, output the number of simple cycles in it. A simple cycle is a cycle with no repeated vertices…

Discription Given a simple graph, output the number of simple cycles in it. A simple cycle is a cycle with no repeated vertices or edges. Input The first line of input contains two integers n and m (1 ≤ n ≤ 19, 0 ≤ m) – respectively the number of ver…

题目描述:  A Simple Task time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Given a simple graph, output the number of simple cycles in it. A simple cycle is a cycle with no repeated vertices or…

E. A Simple Task Problem's Link: http://codeforces.com/problemset/problem/558/E Mean: 给定一个字符串,有q次操作,每次操作将(l,r)内的字符升序或降序排列,输出q次操作后的字符串. analyse: 基本思想是计数排序. 所谓计数排序,是对一个元素分布较集中的数字集群进行排序的算法,时间复杂度为O(n),但使用条件很苛刻.首先对n个数扫一遍,映射出每个数字出现的次数,然后再O(n)扫一遍处理出:对于数字ai,…

题目链接:http://codeforces.com/contest/558/problem/E E. A Simple Task time limit per test5 seconds memory limit per test512 megabytes inputstandard input outputstandard output   This task is very simple. Given a string S of length n and q queries each qu…

题目链接  A Simple Task 题意  给出一个小写字母序列和若干操作.每个操作为对给定区间进行升序排序或降序排序. 考虑权值线段树. 建立26棵权值线段树.每次操作的时候先把26棵线段树上的所有在该区间内的信息清空. 然后再通过类似计数排序的方式从左往右(或从右往左)依次塞进去. #include <bits/stdc++.h> using namespace std; #define rep(i, a, b) for (int i(a); i <= (b); ++i) #de…

题目描述: Description This task is very simple. Given a string S of length n and q queries each query is on the format i j k which means sort the substring consisting of the characters from i to j in non-decreasing order if k = 1 or in non-increasing ord…

http://codeforces.com/problemset/problem/558/E Examples input 1 abacdabcda output 1 cbcaaaabdd input 2 agjucbvdfk output 2 abcdfgjkuv 题意:给出一个字母的序列(只包含小写字母),每次对它的一个区间进行排序(递增或递减),问最后的字母序列. 自闭题,身为蒟蒻的我读完题后单纯的觉得这题如名字一一样一个简单的任务(完全没有意识到问题的严重性),直接sort走起,结果..…

This task is very simple. Given a string S of length n and q queries each query is on the format i j k which means sort the substring consisting of the characters from i to j in non-decreasing order if k = 1 or in non-increasing order if k = 0. Outpu…