bzoj1027: [JSOI2007]合金

 1 #include<cstdio>
 2 #include<iostream>
 3 #include<cstring>
 4 #include<algorithm>
 5 #include<cmath>
 6 #define rep(i,l,r) for(int i=l;i<=r;++i)
 7 using namespace std;
 8 const int N=520;
 9 typedef double d;
10 int n,m,ans,f[N][N],flag;
11 d c;
12 struct point{
13     d x,y;
14 }a[N],b[N];
15 typedef point vector;
16 const d eps=1e-7;
17 vector operator - (point a,point b){
18     return (vector){a.x-b.x,a.y-b.y};
19 }
20 d cross(vector a,vector b){
21     return a.x*b.y-a.y*b.x;
22 }
23 d cross(point a,point b,point c){  
24     return cross(b-a,c-a);
25 }
26 d dot(vector a,vector b){
27     return a.x*b.x+a.y*b.y;
28 }
29 d dot(point a,point b,point c){
30     return dot(b-a,c-a);
31 }
32 int main(){
33     scanf("%d%d",&n,&m);
34     rep(i,1,n)scanf("%lf%lf%lf",&a[i].x,&a[i].y,&c);
35     rep(i,1,m)scanf("%lf%lf%lf",&b[i].x,&b[i].y,&c);
36     memset(f,60,sizeof f);
37     rep(i,1,n) rep(j,1,n) {
38         flag=1;
39         rep(k,1,m){
40             c=cross(b[k],a[i],a[j]);
41             if(c>eps||(fabs(c)<eps&&dot(b[k],a[i],a[j])>eps)){
42                 flag=0;
43                 break; 
44             }
45         }
46         if(flag) f[i][j]=1;
47     }
48     rep(k,1,n) rep(i,1,n) rep(j,1,n) f[i][j]=min(f[i][j],f[i][k]+f[k][j]);
49     ans=1e9;
50     rep(i,1,n) ans=min(ans,f[i][i]);
51     printf("%d\n",ans>=1e9?-1:ans);
52 }