bzoj1093

首先缩点
然后半连通其实就是缩点后节点数最多的链
注意这里一定是一条链才一定是半连通
然后重建图拓扑排序上做dp即可

 type node=record
        po,next:longint;
      end;

 var w,e:array[..] of node;
     rd,be,c,f,g,p,q,st,dfn,low:array[..] of longint;
     v:array[..] of boolean;
     s,mo,i,n,m,x,y,j,h,t,ans1,ans2,len:longint;

 function min(a,b:longint):longint;
   begin
     if a>b then exit(b) else exit(a);
   end;

 procedure fadd(x,y:longint);
   begin
     inc(len);
     w[len].po:=y;
     w[len].next:=q[x];
     q[x]:=len;
   end;

 procedure add(x,y:longint);
   begin
     inc(len);
     e[len].po:=y;
     e[len].next:=p[x];
     p[x]:=len;
   end;

 procedure tarjan(x:longint);
   var i,y:longint;
   begin
     inc(h);
     dfn[x]:=h;
     low[x]:=h;
     inc(t);
     st[t]:=x;
     v[x]:=true;
     i:=p[x];
     while i<> do
     begin
       y:=e[i].po;
       if dfn[y]= then
       begin
         tarjan(y);
         low[x]:=min(low[x],low[y]);
       end
       else if v[y] then low[x]:=min(low[x],low[y]);
       i:=e[i].next;
     end;
     if dfn[x]=low[x] then
     begin
       inc(s);
       while st[t+]<>x do
       begin
         y:=st[t];
         v[y]:=false;
         inc(c[s]);
         be[y]:=s;
         dec(t);
       end;
     end;
   end;

 begin
   readln(n,m,mo);
   for i:= to m do
   begin
     readln(x,y);
     add(x,y);
   end;
   for i:= to n do
     if dfn[i]= then
     begin
       h:=;
       t:=;
       tarjan(i);
     end;

   len:=;
   for i:= to n do
   begin
     j:=p[i];
     while j<> do
     begin
       y:=e[j].po;
       if be[y]<>be[i] then
       begin
         fadd(be[i],be[y]);
         inc(rd[be[y]]);
       end;
       j:=e[j].next;
     end;
   end;
   t:=;
   for i:= to s do
     if rd[i]= then
     begin
       inc(t);
       st[t]:=i;
       f[i]:=c[i];
       g[i]:=;
     end;
   h:=;
   fillchar(low,sizeof(low),);
   while h<=t do
   begin
     x:=st[h];
     i:=q[x];
     while i<> do
     begin
       y:=w[i].po;
       dec(rd[y]);
       if rd[y]= then
       begin
         inc(t);
         st[t]:=y;
       end;
       if low[y]<>x then
       begin
         low[y]:=x;
         if f[y]<f[x]+c[y] then
         begin
           f[y]:=f[x]+c[y];
           g[y]:=g[x];
         end
         else if f[y]=f[x]+c[y] then g[y]:=(g[y]+g[x]) mod mo;
       end;
       i:=w[i].next;
     end;
     inc(h);
   end;
   ans1:=;
   ans2:=;
   for i:= to s do
     if f[i]>ans1 then
     begin
       ans1:=f[i];
       ans2:=g[i];
     end
     else if f[i]=ans1 then ans2:=(ans2+g[i]) mod mo;
   writeln(ans1);
   writeln(ans2);
 end.