剑鱼行动

剑鱼行动

Time Limit:10000MS  Memory Limit:65536K
Total Submit:90 Accepted:77
Case Time Limit:1000MS

Description

给出N个点的坐标，对它们建立一个最小生成树，代价就是连接它们的路径的长度，现要求总长度最小。N的值在100以内，坐标值在[-10000,10000].结果保留二位小数

Input

5 ---------------5个点
0 0 ---------------5个点点的坐标
0 1
1 1
1 0
0.5 0.5

Output

2.83

Sample Input

Sample Output

Source

zju

 

 

 

var
 a:array [0..101,0..101] of extended;
 v:array [0..101] of longint;
 x,y:array [0..101] of extended;
 i,j,k,n,t,p,q:longint;
 min,ans:extended;
begin
 readln(n);
 for i:=1 to n do
  begin
   readln(x[i],y[i]);
   v[i]:=i;
  end;
   for i:=1 to n do
    for j:=1 to n do
     if i<>j then a[i,j]:=sqrt(abs(x[i]-x[j])*abs(x[i]-x[j])+abs(y[i]-y[j])*abs(y[i]-y[j]));
   for k:=1 to n-1 do
    begin
     min:=maxlongint;
     for i:=1 to n do
      for j:=1 to n do
       if (v[i]<>v[j]) and (a[i,j]<min) and (a[i,j]<>0) then begin
                                                              min:=a[i,j];
                                                              p:=j;
                                                              q:=i;
                                                             end;
       ans:=ans+min;
       t:=v[p];
    for i:=1 to n do if v[i]=t then v[i]:=v[q];
     end;
  writeln(ans:0:2);
end.