OJ-Problems-Source/HDOJ/1245_autoAC.cpp
2016-08-13 17:16:08 +08:00

95 lines
2.1 KiB
C++

#include<stdio.h>
#include<math.h>
#include<queue>
using namespace std;
const int MAXN=110;
const double MAXNUM=1e8;
int n,step[MAXN];
double x[MAXN],y[MAXN];
double d,dis[MAXN],map[MAXN][MAXN];
bool mark[MAXN];
double dist(int i,int j)
{
double X=(x[i]-x[j])*(x[i]-x[j]);
double Y=(y[i]-y[j])*(y[i]-y[j]);
return sqrt(X+Y);
}
void SPFA()
{
int i;
queue<int> q;
for(i=1;i<=n+1;i++)
{
dis[i]=MAXNUM;
mark[i]=0;
}
step[0]=0;
dis[0]=0.0;
q.push(0);
mark[0]=1;
while(!q.empty())
{
int s=q.front();
q.pop();
mark[s]=0;
for(i=1;i<=n+1;i++)
{
if(map[s][i]<=d&&map[s][i]+dis[s]<dis[i])
{
dis[i]=map[s][i]+dis[s];
step[i]=step[s]+1;
if(!mark[i])
q.push(i);
}
else if(map[s][i]<=d&&dis[i]==map[s][i]+dis[s])
{
if(step[i]>step[s]+1)
{
step[i]=step[s]+1;
if(!mark[i])
q.push(i);
}
}
}
}
}
int main()
{
while(scanf("%d%lf",&n,&d)==2)
{
int i,j;
x[0]=y[0]=0;
for(i=1;i<=n;i++)
scanf("%lf%lf",x+i,y+i);
if(d>=42.50)
{
puts("42.50 1");
continue;
}
for(i=1;i<=n;i++)
{
map[i][i]=MAXNUM;
for(j=i+1;j<=n;j++)
map[i][j]=map[j][i]=dist(i,j);
}
for(i=1;i<=n;i++)
{
map[i][0]=0.0;
map[0][i]=sqrt(x[i]*x[i]+y[i]*y[i])-7.5;
}
for(i=1;i<=n;i++)
{
map[n+1][i]=0.0;
if(50.00-fabs(x[i])>50.00-fabs(y[i]))
map[i][n+1]=50.00-fabs(y[i]);
else map[i][n+1]=50.00-fabs(x[i]);
}
map[0][n+1]=MAXNUM;
SPFA();
if(dis[n+1]==MAXNUM)
puts("can't be saved");
else printf("%.2lf %d\n",dis[n+1],step[n+1]);
}
return 0;
}