dinic模板

 procedure addedge(u,v,cap:longint);
   begin
     sid[tot].u:=u;
     sid[tot].v:=v;
     sid[tot].cap:=cap;
     sid[tot].next:=nd[u];
     nd[u]:=tot;
     inc(tot);
     sid[tot].u:=v;
     sid[tot].v:=u;
     sid[tot].cap:=0;
     sid[tot].next:=nd[v];
     nd[v]:=tot;
     inc(tot);
   end;

 function bfs:boolean;
 var
  i,head,tail,u,p:longint;
   begin
     for i:=0 to n*m+1 do
       dep[i]:=-1;
     dep[0]:=0;
     head:=1;tail:=1;dl[1]:=0;
     while head<=tail do
       begin
         u:=dl[head];
         p:=nd[dl[head]];
         while p<>-1 do
           begin
             if (sid[p].cap>0) and (dep[sid[p].v]=-1) then
               begin
                 dep[sid[p].v]:=dep[u]+1;
                 if sid[p].v=n*m+1 then exit(true);
                 inc(tail);
                 dl[tail]:=sid[p].v;
               end;
             p:=sid[p].next;
           end;
         inc(head);
       end;
     exit(false);
   end;

 function dinic:longint;
 var
  top,i,u,mi,last:longint;
   begin
     dinic:=0;
     while bfs do
       begin
         fillchar(stack,sizeof(stack),0);
         top:=0;
         for i:=0 to n*m+1 do cur[i]:=nd[i];
         u:=0;
         while true do
           begin
             if u=n*m+1 then
               begin

                 mi:=maxlongint;
                 for i:=1 to top do
                   begin
                     if sid[stack[i]].cap<mi then
                       begin
                         last:=i;
                         mi:=sid[stack[i]].cap;
                       end;
                   end;

                 for i:=1 to top do
                   begin
                     dec(sid[stack[i]].cap,mi);
                     inc(sid[stack[i] xor 1].cap,mi);
                   end;

                 top:=last-1;
                 dinic:=dinic+mi;
                 u:=sid[stack[last]].u;
               end;

              while cur[u]<>-1 do
                begin
                  if (dep[sid[cur[u]].v]=dep[u]+1) and (sid[cur[u]].cap<>0) then break
                  else  cur[u]:=sid[cur[u]].next;
                end;

             if cur[u]=-1 then
               begin
                 if u=0 then break;
                 dep[u]:=-1;
                 u:=sid[stack[top]].u;
                 dec(top);
               end else
               begin
                 inc(top);
                 stack[top]:=cur[u];
                 u:=sid[cur[u]].v;
               end;
           end;
       end;
   end;

最大流=最小割=正点权和-最大闭合权图

其中求最大闭合权图时，源点向所有点权为正的点连容量为点权的边，所有点权为负的点向汇点连容量为点权绝对值的边

表示约束关系的边容量为无穷大,i前必须做j，i连向j

-----------------------------------------------------------------------------------------------

  void addedge2(int u,int v,int cap){
      sid[cnt].next=nd[u];sid[cnt].des=v;sid[cnt].cap=cap;nd[u]=cnt;sid[cnt].fr=u;cnt++;
      sid[cnt].next=nd[v];sid[cnt].des=u;sid[cnt].cap=;nd[v]=cnt;sid[cnt].fr=v;cnt++;
  }

   int bfs(){
      memset(dep,-,sizeof(dep));

      int head=,tail=;
      dep[sor]=;dl[head]=sor;
      while (head<=tail){
        for (int p=nd[dl[head]];p!=-;p=sid[p].next)
          if ((dep[sid[p].des]==-)&&(sid[p].cap)) dep[sid[p].des]=dep[dl[head]]+,dl[++tail]=sid[p].des;
        head++;
    }

    if (dep[tar]==-) return();else return();
  }

  int dinic(){
      int maxflow=;
      while (bfs()){
          for (int i=;i<=tar;i++) cur[i]=nd[i];

          int u=sor,top=;
while(){
              if (u==tar){
                  int mi=1e9,last;
                  for (int i=;i<=top;i++)
                    if (sid[sta[i]].cap<mi)
                    {mi=sid[sta[i]].cap;last=i;}

                  for (int i=;i<=top;i++)
                  sid[sta[i]].cap-=mi,sid[sta[i]^].cap+=mi;
                u=sid[sta[last]].fr;cur[u]=sid[cur[u]].next;top=last-;
                maxflow+=mi;
                continue;
            }

            while((cur[u]!=-)&&((sid[cur[u]].cap==)||(dep[sid[cur[u]].des]!=dep[u]+)))
              cur[u]=sid[cur[u]].next;

            if (cur[u]!=-){sta[++top]=cur[u];u=sid[cur[u]].des;continue;}
            else{
                if (u==sor) break;
                dep[u]=-;
                u=sid[sta[top--]].fr;
                continue;
            }
          }
      }
      return(maxflow);
  }