服务点设置问题

program djsb;
var
        x,y,z,n,m,i:longint;
        b:array[1..200,0..200]of longint;
        a:array[1..200,1..200]of longint;
        dist:array[1..200,1..200]of longint;
        t:array[1..30000]of integer;
procedure init;
begin
        assign(input,'djsb.in');
        reset(input);
        assign(output,'djsb.out');
        rewrite(output);
        readln(n,m);
        fillchar(b,sizeof(b),0);
        fillchar(a,sizeof(a),0);
        for i:=1 to m do
        begin
                readln(x,y,z);
                inc(x);
                inc(y);
                inc(b[x,0]);
                b[x,b[x,0]]:=y;
                inc(b[y,0]);
                b[y,b[y,0]]:=x;
                a[x,y]:=z;
                a[y,x]:=z;
        end;
end;
procedure closef;
begin
        close(input);
        close(output);
end;
procedure spfa(st:integer);
var
        now,i,head,tail:integer;
        v:array[1..100]of boolean;
begin
        head:=0;
        tail:=1;
        fillchar(v,sizeof(v),false);
        fillchar(t,sizeof(t),0);
        t[1]:=st;
        for i:=1 to n do dist[st,i]:=maxint;
        dist[st,st]:=0;


        v[st]:=true;
        repeat
                inc(head);
                now:=t[head];
                for i:=1 to b[now,0] do
                 if dist[st,b[now,i]]>dist[st,now]+a[now,b[now,i]] then
                  begin
                        dist[st,b[now,i]]:=dist[st,now]+a[now,b[now,i]];
                        if not(v[b[now,i]])then
                         begin
                                inc(tail);
                                t[tail]:=b[now,i];
                                v[b[now,i]]:=true;
                         end;
                  end;
               v[now]:=false;
        until head>=tail;
end;
procedure main;
var
        max,k,i,j,min,p1,p2,now1,now2:longint;
begin
        min:=maxlongint;
        for i:=1 to n do
         spfa(i);
        for i:=1 to n-1 do
         for j:=i+1 to n do if i<>j then
          begin
                now1:=-1;now2:=-1;


                for k:=1 to n do if (k<>i)and(k<>j) then
                begin
                 if dist[i,k]>dist[j,k] then
                  begin
                        if dist[j,k]>now2 then now2:=dist[j,k];
                  end   else if dist[i,k]<dist[j,k] then
                   if dist[i,k]>now1 then now1:=dist[i,k];
                   if dist[i,k]=dist[j,k] then
                   begin
                        if dist[i,k]>now1 then now1:=dist[i,k];
                        if dist[j,k]>now2 then now2:=dist[j,k];
                   end;
                end;
                if now1>now2 then max:=now1 else max:=now2;
                if max<min then
                begin
                        min:=max;
                        p1:=i;
                        p2:=j;
                end;
          end;
        writeln(p1-1,' ',p2-1);
end;
begin
        init;
        main;
        closef;
end.
p服务点 还没做出来