最小/大费用最大流模板(codevs1914)

     void addedge(int fr,int to,int cap,int cos){
         sid[cnt].fr=fr;sid[cnt].des=to;sid[cnt].cap=cap;sid[cnt].cos=cos;sid[cnt].next=nd[fr];nd[fr]=cnt++;
         sid[cnt].fr=to;sid[cnt].des=fr;sid[cnt].cap=0;sid[cnt].cos=-cos;sid[cnt].next=nd[to];nd[to]=cnt++;
     }
     
    int spfa(){
        dl[head=tail=1]=sor;
        for (int i=1;i<=n+2;i++) dis[i]=1e9;
        for (int i=0;i<=n+2;i++) b[i]=0;
        for (int i=0;i<=n+2;i++) count[i]=0;
        b[sor]=1;
        dis[sor]=0;
        while (head<=tail){
            for (int p=nd[dl[head]];p!=-1;p=sid[p].next)
                if ((sid[p].cap!=0)&&(dis[sid[p].des]>dis[dl[head]]+sid[p].cos)){
                    path[sid[p].des]=p;
                    if (b[sid[p].des]==0){
                        dl[++tail]=sid[p].des;
                        b[sid[p].des]=1;
                        count[sid[p].des]++;
                    }
                    dis[sid[p].des]=dis[dl[head]]+sid[p].cos;
                }
                b[dl[head++]]=0;        
        }
        
        if (dis[tar]==1e9) return(0);else return(1);
    }
    
    void aug(){
        int po=tar,flow=1e9;

        while (po!=sor){
            int p=path[po];
            flow=min(flow,sid[p].cap);
            po=sid[p].fr;
        }
            
        po=tar;
        
        while (po!=sor){
            int p=path[po];
            sid[p].cap-=flow;
            ans+=flow*sid[p].cos;
            sid[p^1].cap+=flow;
            po=sid[p].fr;
        }
    }

最小费用最大流

uses math;

var
 n,m,i,j :longint;
 ans:int64;
 dl:array[1..50000] of longint;
 cost,tcap,cap:array[0..501,0..501] of int64;
 dis:array[0..501] of longint;
 pre:array[0..501] of longint;
 a,b:array[1..250] of longint;
 c:Array[1..250,1..250] of longint;

 procedure build;
 var
  i,j:longint;
   begin
     for i:=1 to n do
       begin
         cap[0,i]:=maxlongint;
         cost[0,i]:=0;
       end;

     for i:=1 to n do
       begin
         cap[i,i+n]:=a[i];
         cost[i,i+n]:=0;
       end;

     for i:=1 to n do
       for j:=1 to m do
         begin
           cap[i+n,j+2*n]:=maxlongint;
           cost[i+n,j+2*n]:=c[i,j];
           cost[j+2*n,i+n]:=-c[i,j];
         end;

     for i:=1 to m do
       begin
         cap[i+2*n,i+2*n+m]:=b[i];
         cost[i+2*n,i+2*n+m]:=0;
       end;

     for i:=1 to m do
       begin
         cap[i+2*n+m,2*n+2*m+1]:=maxlongint;
         cost[i+2*n+m,2*n+2*m+1]:=0;
       end;
   end;

  procedure aug;
  var
   po:longint;
   mi:int64;
   pr:longint;
    begin
      po:=2*n+2*m+1;
      mi:=maxlongint;
      while po<>0 do
        begin
          pr:=pre[po];
          mi:=min(mi,tcap[pr,po]);
          po:=pr;
        end;

      po:=2*n+2*m+1;
      while po<>0 do
        begin
          pr:=pre[po];
          dec(tcap[pr,po],mi);
          inc(tcap[po,pr],mi);
          inc(ans,mi*cost[pr,po]);
          po:=pr;
        end;
    end;

  function spfa1:boolean;
  var
   i,head,tail,u:longint;
    begin
      for i:=1 to 2*m+2*n+1 do
         dis[i]:=maxlongint;
      dis[0]:=0;

      head:=1;tail:=1;
      dl[1]:=0;
      while head<=tail do
        begin
          u:=dl[head];
          for i:=0 to 2*n+2*m+1 do
            if (tcap[u,i]>0) and (dis[i]>dis[u]+cost[u,i]) then
              begin
                pre[i]:=u;
                inc(tail);
                dl[tail]:=i;
                dis[i]:=dis[u]+cost[u,i];
              end;
          inc(head);
        end;

      if dis[2*n+2*m+1]=maxlongint then  exit(false) else exit(true);
    end;

  begin

    read(n,m);

    for i:=1 to n do
      read(a[i]);
    for i:=1 to m do
      read(b[i]);
    for i:=1 to n do
      for j:=1 to m do
        read(c[i,j]);

    build;

    for i:=0 to 2*n+2*m+1 do
      for j:=0 to 2*n+2*m+1 do
          tcap[i,j]:=cap[i,j];
    while spfa1 do aug;
    writeln(ans);


  end.

最大费用最大流

uses math;

var
 n,m,i,j :longint;
 ans:int64;
 dl:array[1..50000] of longint;
 cost,tcap,cap:array[0..501,0..501] of int64;
 dis:array[0..501] of longint;
 pre:array[0..501] of longint;
 a,b:array[1..250] of longint;
 c:Array[1..250,1..250] of longint;

 procedure build;
 var
  i,j:longint;
   begin
     for i:=1 to n do
       begin
         cap[0,i]:=maxlongint;
         cost[0,i]:=0;
       end;

     for i:=1 to n do
       begin
         cap[i,i+n]:=a[i];
         cost[i,i+n]:=0;
       end;

     for i:=1 to n do
       for j:=1 to m do
         begin
           cap[i+n,j+2*n]:=maxlongint;
           cost[i+n,j+2*n]:=c[i,j];
           cost[j+2*n,i+n]:=-c[i,j];
         end;

     for i:=1 to m do
       begin
         cap[i+2*n,i+2*n+m]:=b[i];
         cost[i+2*n,i+2*n+m]:=0;
       end;

     for i:=1 to m do
       begin
         cap[i+2*n+m,2*n+2*m+1]:=maxlongint;
         cost[i+2*n+m,2*n+2*m+1]:=0;
       end;
   end;

  procedure aug;
  var
   po:longint;
   mi:int64;
   pr:longint;
    begin
      po:=2*n+2*m+1;
      mi:=maxlongint;
      while po<>0 do
        begin
          pr:=pre[po];
          mi:=min(mi,tcap[pr,po]);
          po:=pr;
        end;

      po:=2*n+2*m+1;
      while po<>0 do
        begin
          pr:=pre[po];
          dec(tcap[pr,po],mi);
          inc(tcap[po,pr],mi);
          inc(ans,mi*cost[pr,po]);
          po:=pr;
        end;
    end;



  function spfa2:boolean;
  var
   i,u,head,tail:longint;
    begin
      for i:=1 to 2*m+2*n+1 do
         dis[i]:=-maxlongint;
      dis[0]:=0;

      head:=1;tail:=1;
      dl[1]:=0;
      while head<=tail do
        begin
          u:=dl[head];
          for i:=0 to 2*n+2*m+1 do
            if (tcap[u,i]>0) and (dis[i]<dis[u]+cost[u,i]) then
              begin
                pre[i]:=u;
                inc(tail);
                dl[tail]:=i;
                dis[i]:=dis[u]+cost[u,i];
              end;
          inc(head);
        end;

      if dis[2*n+2*m+1]=-maxlongint then  exit(false) else exit(true);
    end;

  begin

    read(n,m);

    for i:=1 to n do
      read(a[i]);
    for i:=1 to m do
      read(b[i]);
    for i:=1 to n do
      for j:=1 to m do
        read(c[i,j]);

    build;

    ans:=0;
    for i:=0 to 2*n+2*m+1 do
      for j:=0 to 2*n+2*m+1 do
          tcap[i,j]:=cap[i,j];
    while spfa2 do aug;
    writeln(ans);

  end.

边表模板

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

  function spfa:boolean;
  var
   i,head,tail,u,p:longint;
    begin

      for i:=1 to n+1 do dis[i]:=maxlongint div 2;
      for i:=1 to n+1 do vis[i]:=true;

      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 (dis[u]+sid[p].cost<dis[sid[p].v]) then
                begin
                 if vis[sid[p].v]=true then
                  begin
                  inc(tail);
                  dl[tail]:=sid[p].v;
                  vis[sid[p].v]:=false;
                  end;
                  pre[sid[p].v]:=p;
                  dis[sid[p].v]:=dis[u]+sid[p].cost;
                end;
              p:=sid[p].next;
            end;
          vis[dl[head]]:=true;
          inc(head);
        end;

      if dis[n+1]=maxlongint div 2 then exit(false) else exit(true);
    end;


  procedure aug;
  var
   po,mi:longint;
    begin
      po:=n+1;
      mi:=maxlongint;
      while po<>0 do
        begin
          if sid[pre[po]].cap<mi then mi:=sid[pre[po]].cap;
          po:=sid[pre[po]].u;
        end;

      po:=n+1;
      while po<>0 do
        begin
          inc(ans,mi*sid[pre[po]].cost);
          dec(sid[pre[po]].cap,mi);
          inc(sid[pre[po] xor 1].cap,mi);
          po:=sid[pre[po]].u;
        end;
    end;

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

BZOJ4276

用线段树优化费用流

#include <cstdio>
#include <iostream>
using namespace std;

  struct edge{
      int fr,des,cap,cos,next;
  }sid[400001];
  
  struct treenode{
      int l,r,lc,rc;
  }tr[20001];
  
  int cnt,nd[40001],dl[4000001],head,tail,sor,tar,dis[40001],b[40001],path[40001],ans,scnt;

     void addedge(int fr,int to,int cap,int cos){
         sid[scnt].fr=fr;sid[scnt].des=to;sid[scnt].cap=cap;sid[scnt].cos=cos;sid[scnt].next=nd[fr];nd[fr]=scnt++;
         sid[scnt].fr=to;sid[scnt].des=fr;sid[scnt].cap=0;sid[scnt].cos=-cos;sid[scnt].next=nd[to];nd[to]=scnt++;
     }
     
    int spfa(){
        dl[head=tail=1]=sor;
        for (int i=1;i<=tar;i++) dis[i]=0,b[i]=0;
        b[sor]=1;
        dis[sor]=0;
        while (head<=tail){
            for (int p=nd[dl[head]];p!=-1;p=sid[p].next)
                if ((sid[p].cap!=0)&&(dis[sid[p].des]<dis[dl[head]]+sid[p].cos)){
                    path[sid[p].des]=p;
                    if (b[sid[p].des]==0){
                        dl[++tail]=sid[p].des;
                        b[sid[p].des]=1;
                    }
                    dis[sid[p].des]=dis[dl[head]]+sid[p].cos;
                }
                b[dl[head++]]=0;        
        }
        
        if (dis[tar]==0) return(0);else return(1);
    }
    
    void aug(){
        int po=tar,flow=1e9;

        while (po!=sor){
            int p=path[po];
            flow=min(flow,sid[p].cap);
            po=sid[p].fr;
        }
            
        po=tar;
        
        while (po!=sor){
            int p=path[po];
            sid[p].cap-=flow;
            ans+=flow*sid[p].cos;
            sid[p^1].cap+=flow;
            po=sid[p].fr;
        }
    }
    
  void build(int l,int r){
      tr[++cnt].l=l;tr[cnt].r=r;
      if (l==r) {addedge(cnt,tar,1,0);return;}
      
      int t=cnt,mid=(l+r)>>1;
      tr[t].lc=cnt+1;addedge(t,cnt+1,1e9,0);
      build(l,mid);
      tr[t].rc=cnt+1;addedge(t,cnt+1,1e9,0);
      build(mid+1,r);
  }
 
  void query(int po,int l,int r,int fr){
      if (tr[po].l==l&&tr[po].r==r){
        addedge(fr,po,1e9,0);return;    
    }
    
    int mid=(tr[po].l+tr[po].r)>>1;
    if (l<=mid) query(tr[po].lc,l,min(mid,r),fr);
    if (r>mid)  query(tr[po].rc,max(mid+1,l),r,fr);
  }

  int main(){      
      int n,t1,t2,t3;
      scanf("%d",&n);
      sor=0;tar=30001;
      for (int i=sor;i<=tar;i++) nd[i]=-1;
      build(1,5000);
      
      for (int i=1;i<=n;i++){
        scanf("%d%d%d",&t1,&t2,&t3);t2--;
      addedge(sor,++cnt,1,t3);    
      query(1,t1,t2,cnt);
    }
    
    while (spfa()) 
      aug();
    
    printf("%d
",ans);
  }