...其实暑假的时候写过一次，不过那时候对这道题理解不是很深，所以重写了一遍....
尝试用新的模版去写，然后发现新的模版里面我把fail并到next，以省去多次的while取点，但是对于这道题，fail是必须用到的，因为要DP...所以不能并进去...于是只能乖乖滚回去写原来的方法，每次都去往回while fail节点...然后就是pd数组的传递，要和fail所连的点保持一直，因为是BFS下来的...
然后...代码如下
1 const maxn=6419; 2 maxs=25; 3 vv=10007; 4 var 5 next:array[0..maxn,0..maxs] of longint; 6 pd:array[0..maxn] of boolean; 7 f:array[0..maxn] of longint; 8 q:array[0..maxn] of longint; 9 dp:array[0..maxn,0..105] of longint;10 s:string;11 head,tail,root,n,m,tot:longint;12 13 procedure push(x:longint); begin inc(tail); q[tail]:=x; end;14 15 function new:longint;16 var i:longint;17 begin18 pd[tot]:=false;19 for i:= 0 to maxs do next[tot,i]:=-1;20 inc(tot); exit(tot-1);21 end;22 23 procedure insert(s:string);24 var c,i,v:longint;25 begin26 v:=root;27 for i:= 1 to length(s) do28 begin29 c:=ord(s[i])-65;30 if next[v,c]=-1 then next[v,c]:=new;31 v:=next[v,c];32 end;33 pd[v]:=true;34 end;35 36 procedure build;37 var v,tmp,i:longint;38 begin39 f[root]:=root;40 head:=1; tail:=0;41 for i:= 0 to maxs do42 if next[root,i]<>-1 then43 begin f[next[root,i]]:=root; push(next[root,i]); end;44 while head<=tail do45 begin46 v:=q[head]; inc(head);47 for i:= 0 to maxs do48 if next[v,i]<>-1 then49 begin50 push(next[v,i]);51 tmp:=f[v];52 while (tmp<>root) and (next[tmp,i]=-1) do tmp:=f[tmp];53 if next[tmp,i]<>-1 then tmp:=next[tmp,i];54 if tmp=-1 then f[next[v,i]]:=root else f[next[v,i]]:=tmp;55 if not pd[next[v,i]] then pd[next[v,i]]:=pd[tmp];56 end;57 end;58 end;59 60 procedure solve;61 var i,j,k,v,cnt,ans:longint;62 begin63 dp[0,0]:=1;64 for i:= 1 to m do65 for j:= root to tot do66 if (not pd[j]) and (dp[j,i-1]>0) then67 for k:= 0 to maxs do68 begin69 v:=j;70 while (next[v,k]=-1) and (v<>root) do v:=f[v];71 if next[v,k]<>-1 then v:=next[v,k];72 if not pd[v] then dp[v,i]:=(dp[v,i]+dp[j,i-1]) mod vv;73 end;74 cnt:=0;75 for i:= 0 to tot do cnt:=(cnt+dp[i,m]) mod vv;76 ans:=1;77 for i:= 1 to m do ans:=(ans*26) mod vv;78 ans:=(((ans-cnt) mod vv+vv) mod vv);79 writeln(ans);80 end;81 82 procedure init;83 var i:longint;84 begin85 readln(n,m);86 root:=new;87 for i:= 1 to n do88 begin89 readln(s);90 insert(s);91 end;92 build;93 end;94 95 Begin96 init;97 solve98 End.