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摘要： 一开始完全看不出这是AC自动机啊。求长度为T且不包含长度大于K的回文串的二进制串有多少种。枚举长度为K和K+1的全部回文串，保存在tire里面，然后构造自动机DP因为长度>k+1的肯定也包含这些长度为K或K+1的。//#pragma comment(linker, "/STACK:1024000000,1024000000")#include#include#include#include#include#include#include#include#include#include#include#include#include#includeusing names 阅读全文

摘要： 如果把一颗树跑一遍拓扑排序，会发现每颗子树都在一个区间里。那么对子树的操作就变成对区间的操作。#include#include#include#include#includeusing namespace std;const int MAXN=100100;int n,m;int t;int id[MAXN];int num[MAXN];vector g[MAXN];int calnum(int u){ int x=1; for(int i=0;i>1; flag[idx=r) { flag[idx]^=1; sum[idx]=r-l... 阅读全文

摘要： //#pragma comment(linker, "/STACK:1024000000,1024000000")#include#include#include#include#include#include#include#include#include#include#include#include#include#includeusing namespace std;typedef long long ll;typedef unsigned long long ull;typedef pair pii;#define pb(a) push_back(a)#defin 阅读全文

摘要： //#pragma comment(linker, "/STACK:1024000000,1024000000")#include#include#include#include#include#include#include#include#include#include#include#include#include#includeusing namespace std;typedef long long ll;typedef unsigned long long ull;typedef pair pii;#define pb(a) push_back(a)#defin 阅读全文

摘要： 时间卡得紧，写成递推可以做一些优化//#pragma comment(linker, "/STACK:1024000000,1024000000")#include#include#include#include#include#include#include#include#include#include#include#include#include#includeusing namespace std;typedef long long ll;typedef unsigned long long ull;typedef pair pii;#define pb(a) p 阅读全文