bzoj2893

有起点终点的限制的路径覆盖
首先tarjan缩点成DAG
似乎不能按照二分匹配的做法做
那么建立源汇拆点i,i'，这两点之间连一条下界为1上界无穷的边，
其它边都是下界为0，上界正无穷
然后就是有源有汇的最小流，之前在bzoj2502介绍过

const inf=10000007;
type node=record
       po,flow,next:longint;
     end;

var w,e:array[0..200010] of node;
    be,p,q,c,dfn,low,cur,a,b:array[0..2010] of longint;
    v,f:array[0..2010] of boolean;
    na,nb,h,ss,tt,t,te,s,len,n,m,i,x,y,j:longint;

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

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

procedure build(x,y,f:longint);
  begin
    inc(len);
    e[len].po:=y;
    e[len].flow:=f;
    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;
    v[x]:=true;
    inc(t);
    c[t]:=x;
    f[x]:=true;
    i:=q[x];
    while i<>0 do
    begin
      y:=w[i].po;
      if not v[y] then
      begin
        tarjan(y);
        low[x]:=min(low[x],low[y]);
      end
      else if f[y] then low[x]:=min(low[x],low[y]);
      i:=w[i].next;
    end;
    if low[x]=dfn[x] then
    begin
      inc(s);
      while c[t+1]<>x do
      begin
        y:=c[t];
        be[y]:=s;
        f[y]:=false;
        dec(t);
      end;
    end;
  end;

procedure sap(s,t:longint);
  var q,u,i,j,tmp:longint;
  begin
    fillchar(c,sizeof(c),0);
    fillchar(dfn,sizeof(dfn),0);
    for i:=0 to t do
      cur[i]:=p[i];
    u:=s;
    dfn[0]:=t+1;
    while c[s]<t+1 do
    begin
      i:=cur[u];
      while i<>-1 do
      begin
        j:=e[i].po;
        if (e[i].flow>0) and (c[u]=c[j]+1) then
        begin
          cur[u]:=i;
          low[j]:=u;
          u:=j;
          if u=t then
          begin
            while u<>s do
            begin
              u:=low[u];
              j:=cur[u];
              dec(e[j].flow);
              inc(e[j xor 1].flow);
            end;
          end;
          break;
        end;
        i:=e[i].next;
      end;
      if i=-1 then
      begin
        dec(dfn[c[u]]);
        if dfn[c[u]]=0 then exit;
        q:=-1;
        tmp:=t;
        i:=p[u];
        while i<>-1 do
        begin
          j:=e[i].po;
          if e[i].flow>0 then
            if c[j]<tmp then
            begin
              q:=i;
              tmp:=c[j];
            end;
          i:=e[i].next;
        end;
        cur[u]:=q;
        c[u]:=tmp+1;
        inc(dfn[c[u]]);
        if u<>s then u:=low[u];
      end;
    end;
  end;

function check:boolean;
  var i:longint;
  begin
    i:=p[ss];
    while i<>-1 do
    begin
      if (e[i].flow>0) and (e[i].po<>t) then exit(false);
      i:=e[i].next;
    end;
    exit(true);
  end;

begin
  readln(te);
  while te>0 do
  begin
    dec(te);
    len:=0;
    fillchar(p,sizeof(p),255);
    fillchar(q,sizeof(q),0);
    readln(n,m,na,nb);
    for i:=1 to na do
      read(a[i]);
    for i:=1 to nb do
      read(b[i]);
    for i:=1 to m do
    begin
      readln(x,y);
      add(x,y);
    end;
    fillchar(v,sizeof(v),false);
    fillchar(f,sizeof(f),false);
    fillchar(c,sizeof(c),0);
    s:=0;
    for i:=1 to n do
      if not v[i] then
      begin
        h:=0;
        t:=0;
        tarjan(i);
      end;
    len:=-1;
    t:=2*s+1;
    ss:=2*s+2;
    tt:=2*s+3;
    for i:=1 to na do
    begin
      build(0,be[a[i]],inf);
      build(be[a[i]],0,0);
    end;
    for i:=1 to nb do
    begin
      build(be[b[i]]+s,t,inf);
      build(t,be[b[i]]+s,0);
    end;
    for i:=1 to n do
    begin
      j:=q[i];
      while j<>0 do
      begin
        y:=be[w[j].po];
        if y<>be[i] then
        begin
          build(be[i]+s,y,inf);
          build(y,be[i]+s,0);
        end;
        j:=w[j].next;
      end;
    end;
    for i:=1 to s do
    begin
      build(i,i+s,inf);
      build(i+s,i,0);
      build(ss,i+s,1);
      build(i+s,ss,0);
      build(i,tt,1);
      build(tt,i,0);
    end;
    sap(ss,tt);
    build(t,0,inf);
    build(0,t,0);
    sap(ss,tt);
    if check then writeln(e[len].flow)
    else writeln('no solution');
  end;
end.