hdu 4463 最小生成树 prim

打代码太大意了.....

#include<stdio.h>
#include<math.h>
#define INF 99999999
double map[600][600],dis[600],book[600];
struct edge
{
int x,y;
}e[100];
int n,p,q;
int abs(int x)
{
return x>0?x:-x;
}
double D(int x1,int y1,int x2,int y2) //2点间距
{
double s;
int x=abs(x1-x2);
int y=abs(y1-y2);
s=x*x+y*y;
return sqrt(s);
}
int main()
{
while(scanf("%d",&n),n)
{
scanf("%d%d",&p,&q);
for(int i=1;i<=n;i++)
{
scanf("%d %d",&e[i].x,&e[i].y);
}

for(int i=1;i<=n;i++)//////
{
for(int j=1;j<=n;j++)
{
map[i][j]=INF;
}
}

for(int i=1;i<=n;i++)
{
for(int j=1;j<=n;j++)
{
map[i][j]=map[j][i]=D(e[i].x,e[i].y,e[j].x,e[j].y);
}
}
map[p][q]=map[q][p]=0;
for(int i=1;i<=n;i++)
{
book[i]=0;
dis[i]=map[1][i];
}
book[1]=1;

double sum=0;
int t=n;
double min=INF;
while(t--)
{
int k;
min=INF;
for(int i=1;i<=n;i++)
{
if(book[i]==0&&dis[i]<min)
min=dis[i],k=i;
}
if(min==INF)
break;
book[k]=1;
sum+=min;

for(int j=1;j<=n;j++)
{
if(book[j]==0&&dis[j]>map[k][j])
dis[j]=map[k][j];
}
}
double s=D(e[q].x,e[q].y,e[p].x,e[p].y);
printf("%.2lf\n",sum+s);
}
return 0;
}