实现功能：首行输入N，M，S，T，代表这张图N个点，M条边，源点为S，汇点为T；接下来T行输入个边的出发点、终点和权值；输出最大流

原理：sap网络流算法（详见，个人觉得这个模板已经不错了，虽然本人暂时还未考虑引入邻接表进行优化）（推荐模板题：）

1 var 2    i,j,k,l,m,n,ans,aug,s,t,tmp,jl,mi:longint; 3    flag:boolean; 4    vh,dis,di,his,pre:array[0..10000] of longint; 5    map:array[0..2050,0..2050] of longint; 6 function min(x,y:longint):longint;inline; 7          begin 8               if x
     
      0) and (dis[i]=(dis[j]+1)) then29                             begin30                                  aug:=min(aug,map[i,j]);31                                  pre[j]:=i;di[i]:=j;32                                  i:=j;flag:=true;33                                  if i=t then34                                     begin35                                          ans:=ans+aug;36                                          while i<>s do37                                                begin38                                                     tmp:=i;39                                                     i:=pre[i];40                                                     map[i,tmp]:=map[i,tmp]-aug;41                                                     map[tmp,i]:=map[tmp,i]+aug;42                                                end;43                                          aug:=maxlongint;44                                     end;45                                  break;46                             end;47                     end;48                 if flag then continue;49                 jl:=-1;mi:=n-1;50                 for j:=1 to n do51                     begin52                          if (map[i,j]>0) and (dis[j]
      
       s then64                    begin65                         i:=pre[i];66                         aug:=his[i];67                    end;68            end;69      writeln(ans);70 end.71