https://codeforces.com/problemset/problem/65/D 哈利波特!一种新思路的状压记忆化dfs,记得每次dfs用完要减回去.而且一定是要在dfs外部进行加减!防止在中间return的时候忘记弄回来.用哈希记录状态实现真正的记忆化. #include<bits/stdc++.h> using namespace std; #define ll long long int n; ]; ll getID(int a[]){ ll res=; ;i<;i++…

At the start of each school year, a very important event happens at Hogwarts. Each of the first-year wizards and witches is assigned to one of the four Hogwarts houses. The bravest children are put to Gryffindor, the cleverest are put to Ravenclaw, t…

C. Sorting Railway Cars Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://www.codeforces.com/contest/606/problem/C Description An infinitely long railway has a train consisting of n cars, numbered from 1 to n (the numbers of all the cars are distin…

C. Sorting Railway Cars   An infinitely long railway has a train consisting of n cars, numbered from 1 to n (the numbers of all the cars are distinct) and positioned in arbitrary order. David Blaine wants to sort the railway cars in the order of incr…

Little Elephant and Broken Sorting 怎么感觉这个状态好难想到啊.. dp[ i ][ j ]表示第 i 个数字比第 j 个数字大的概率.转移好像比较显然. #include<bits/stdc++.h> #define LL long long #define LD long double #define ull unsigned long long #define fi first #define se second #define mk make_pair…

C. Sorting Railway Cars time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output An infinitely long railway has a train consisting of n cars, numbered from 1 to n (the numbers of all the cars are d…

Discription The Little Elephant loves permutations of integers from 1 to n very much. But most of all he loves sorting them. To sort a permutation, the Little Elephant repeatedly swaps some elements. As a result, he must receive a permutation 1, 2, 3…

CF258D Little Elephant and Broken Sorting 题意 题意翻译 有一个\(1\sim n\)的排列,会进行\(m\)次操作,操作为交换\(a,b\).每次操作都有\(50\%\)的概率进行. 求进行\(m\)次操作以后的期望逆序对个数. \(n,m\le 1000\) 输入输出格式 输入格式: The first line contains two integers \(n\) and \(m\) \((1\leq n,m\leq 1000,n>1)\) -…

我只能说真的看不懂题解的做法 我的做法就是线段树维护,毕竟每个数的顺序不变嘛 那么单点维护 区间剩余卡片和最小值 每次知道最小值之后,怎么知道需要修改的位置呢 直接从每种数维护的set找到现在需要修改的数的在初始卡片的位置 #include <cstdio> #include <cstdlib> #include <cstring> #include <ctime> #include <algorithm> #include <iostre…

D. Zuma 题目连接: http://www.codeforces.com/contest/608/problem/D Description Genos recently installed the game Zuma on his phone. In Zuma there exists a line of n gemstones, the i-th of which has color ci. The goal of the game is to destroy all the gems…