UVA 11468 "ac Automaton +DP"

DP[I][J] Indicates the probability of walking the I step to the J node. Initial value dp[0][0] = 1. When you go to a node that is not the end of the word, you can walk past it.

!end[i]&&Last[i] = = Root , this node is only feasible.

1#include <bits/stdc++.h>2 using namespacestd;3 Const intN =505;4 intIdCharc) {5     if(c >='0'&&c <='9')returnC-'0';6     if(c >='a'&&c <='Z')returnC-'a'+Ten;7     if(c >='A'&&c <='Z')returnC-'A'+ $;8     return-1;9 }Ten structtire{ One     intnex[n][ +], Fail[n],end[n], last[n]; A     introot, L; -     intNewNode () { -memset (Nex[l],-1,sizeof(Nex[l])); theEND[L] =0; -         returnl++; -     } -     voidinit () { +L =0; -Root =NewNode (); +     } A     voidInsertChar*s) { at         intnow =Root; -          for(inti =0; T[n]; i++){ -             intp =ID (s[i]); -             if(Nex[now][p] = =-1) -NEX[NOW][P] =NewNode (); -now =Nex[now][p]; in         } -End[now] =1; to     } +     voidbuild () { -queue<int>Q; theFail[root] = Last[root] =Root; *          for(inti =0; I < +; i++){ $             int& u =Nex[root][i];Panax Notoginseng             if(U = =-1) -U =Root; the             Else{ +Fail[u] = Last[u] =Root; A q.push (u); the             } +         } -          while(!Q.empty ()) { $             intnow =Q.front (); $ Q.pop (); -              for(inti =0; I < +; i++){ -                 int& u =Nex[now][i]; the                 if(U = =-1) -U =nex[Fail[now]][i];Wuyi                 Else{ theFail[u] =nex[Fail[now]][i]; -Last[u] = end[Fail[u]]?Fail[u]: last[fail[u]; Wu q.push (u); -                 } About             } $         } -     } - }; - Tire ac; A Doublepor[ -]; + Chars[ -]; the Doubledp[ the][n]; - intMain () { $     intN, K, T, CA =1; scanf"%d", &t); the      while(t--){ the ac.init (); thescanf"%d", &k); the          for(inti =0; I < K; i++){ -scanf"%s", s); in Ac.insert (s); the         } the ac.build (); Aboutmemset (Por,0,sizeof(POR)); thescanf"%d", &n); the         Charch; the          for(inti =0; I < n; i++){ +scanf"%c", &ch); -             intp =ID (CH); thescanf"%LF", por+p);Bayi         } the         intL scanf"%d", &l); theMemset (DP,0,sizeof(DP)); -dp[0][0] =1; -          for(inti =0; I < L; i++){ the              for(intj =0; J < AC. L J + +) the                 if(Dp[i][j] >0) for(intK =0; K < +; k++){ the                     intRET =Ac.nex[j][k]; the                     if(!ac.end[ret]&&ac.last[ret] = =ac.root) -dp[i+1][ret] + = dp[i][j]*Por[k]; the                 } the         } the         DoubleAns =0;94          for(inti =0; I < AC. L i++) theAns + =Dp[l][i]; theprintf"Case #%d:%f\n", ca++, ans); the     }98     return 0; About}

UVA 11468 "ac Automaton +DP"