@OceanEye4年前
12/13
01:50
AC自动机上DP
大概要点就是记得取模，其他的都很裸，这个数据范围也是随便跑的。
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#include <cstdio> #include <algorithm> #include <cstring> #include <cstdlib> #include <cmath> #include <iostream> #include <bits/stdc++.h> #define ll long long #define INF 1000000000 #define p(x) ('0'<=x&&x<='9') #define For(i,a,b) for(int i=a;i<=b;++i) #define Rev(i,a,b) for(int i=a;i>=b;--i) char cc; int C; template <class T> void read( T &x ) { x=0; cc=getchar(); C=1; while(!p(cc)) { if(cc=='-') C=-1; cc=getchar(); } while(p(cc)) { x=x*10+cc-48; cc=getchar(); } x*=C; } #undef p #define pb push_back #define pq priority_queue using namespace std; #define N 10010 #define BASE 'A' int root,pcnt; struct node { int sn[26],fail; bool The_end; int& operator[] (const int &x) { return sn[x]; } }pool[N]; int n,m; char s[70][110]; void init() { int node,_; char cur; read(n); read(m); For(i,1,n) scanf("%s",s[i]); root=pcnt=1; For(i,1,n) { node=root; _=0; while(s[i][_]) { cur=s[i][_]-BASE; if(!pool[node][cur]) pool[node][cur]=++pcnt; node=pool[node][cur]; ++_; } pool[node].The_end=1; } pool[1].fail=0; int q[65540],x; unsigned short int he,ta; he=ta=0; q[++he]=1; while(he!=ta) { x=q[++ta]; For(j,0,25) { node=pool[x][j]; if(!node) continue; q[++he]=node; pool[node].The_end|=pool[x].The_end; _=pool[x].fail; while(!pool[_][j]&&_) _=pool[_].fail; pool[node].fail=_?pool[_][j]:root; pool[node].The_end|=pool[pool[node].fail].The_end; } } } #undef BASE #define MOD 10007 int ksm(int x,int t) { int ret=1,cur=x; for(;t;t>>=1) { if(t&1) ret=(ret*cur)%MOD; cur=(cur*cur)%MOD; } return ret; } int ans; int dp[110][N]; bool inq[110][N]; void Tree_DP(int top) { int node,x,dep; pair<int,int> q[65540]; unsigned short int he,ta; he=ta=0; q[++he]=make_pair(1,0); dp[0][1]=1; while(he!=ta) { ++ta; x=q[ta].first; dep=q[ta].second; if(pool[x].The_end) continue; dp[dep][x]%=MOD; if(dep==top) { ans=(ans-dp[dep][x])%MOD; continue; } For(i,0,25) { node=x; while(!pool[node][i]&&node) node=pool[node].fail; node=node?pool[node][i]:root; dp[dep+1][node]+=dp[dep][x]; if(inq[dep+1][node]) continue; q[++he]=make_pair(node,dep+1); inq[dep+1][node]=1; } } } int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); srand(time(NULL)); #ifdef LOCALTEST freopen("input.txt", "r", stdin); #endif init(); Tree_DP(m); printf("%d",(ans+ksm(26,m)+MOD)%MOD); return 0; } |