http://www.lydsy.com/JudgeOnline/problem.php?id=3300 这个细节太多QAQ 只要将所有的括号'('匹配到下一个')'然后dfs即可 简单吧,,, #include <cstdio> #include <cstring> #include <cmath> #include <string> #include <iostream> #include <algorithm> #include…

Description Recently, the cows have been competing with strings of balanced  parentheses and comparing them with each other to see who has the  best one.  Such strings are scored as follows (all strings are balanced): the  string "()" has score…

这是我今天遇到最奇怪的问题,希望有人帮我解释一下... 一开始我能得90分: #include<iostream> #include<cstdio> #include<cmath> #include<ctime> #include<queue> #include<algorithm> #include<stack> #include<cstring> using namespace std; #define d…

3300: [USACO2011 Feb]Best Parenthesis Time Limit: 10 Sec  Memory Limit: 128 MBSubmit: 89  Solved: 42[Submit][Status] Description Recently, the cows have been competing with strings of balanced parentheses and comparing them with each other to see who…

康拓展开/逆展开 模板 #include<algorithm> #include<iostream> #include<cstdio> #define int long long using namespace std; inline int rd(){ int ret=0,f=1;char c; while(c=getchar(),!isdigit(c))f=c=='-'?-1:1; while(isdigit(c))ret=ret*10+c-'0',c=getcha…

[题解] 很容易可以写出朴素DP方程f[i]=sigma f[j] (sum[i]>=sum[j],1<=j<=i).  于是我们用权值树状数组优化即可. #include<cstdio> #include<algorithm> #define N 200010 #define rg register #define LL long long #define Mod (1e9+9) using namespace std; int n,n2; LL t[N],f[…

Time Limit: 10 Sec Memory Limit: 128 MB Description Recently, the cows have been competing with strings of balanced parentheses and comparing them with each other to see who has the best one. Such strings are scored as follows (all strings are balanc…

康托展开 裸的康托展开&逆康托展开 康托展开就是一种特殊的hash,且是可逆的…… 康托展开计算的是有多少种排列的字典序比这个小,所以编号应该+1:逆运算同理(-1). 序列->序号:(康托展开) 对于每个数a[i],数比它小的数有多少个在它之前没出现,记为b[i],$ans=1+\sum b[i]* (n-i)!$ 序号->序列:(逆康托展开) 求第x个排列所对应的序列,先将x-1,然后对于a[i],$\left\lfloor \frac{x}{(n-i)!} \right\rflo…

3301: [USACO2011 Feb] Cow Line Time Limit: 10 Sec  Memory Limit: 128 MBSubmit: 82  Solved: 49[Submit][Status][Discuss] Description The N (1 <= N <= 20) cows conveniently numbered 1...N are playing yet another one of their crazy games with Farmer Joh…

2274: [Usaco2011 Feb]Generic Cow Protests Time Limit: 10 Sec  Memory Limit: 128 MBSubmit: 196  Solved: 122[Submit][Status] Description Farmer John's N (1 <= N <= 100,000) cows are lined up in a row and numbered 1..N. The cows are conducting another…