delete pics to save space

1.2831.cpp

@@ -0,0 +1,53 @@
+#include<cstdio>
+#include<cmath>
+#include<cstring>
+#include<algorithm>
+using namespace std;
+const double eps=1e-7;
+int T,n,m,lines[20][20],must[1<<20],dp[1<<20];
+double x[20],y[20];
+inline void cal(double &x,double &y,double a1,double b1,double c1,double a2,double b2,double c2)
+{
+	y=(a1*c2-a2*c1)/(a1*b2-a2*b1);
+	x=(c1-b1*y)/a1;
+}
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	for(int i=0;i<(1<<18);i++)
+	{
+		int j=1;
+		for(;j<=18&&(i&(1<<(j-1)));j++);
+		must[i]=j;
+	}
+	scanf("%d",&T);
+	while(T-->0)
+	{
+		memset(lines,0,sizeof(lines));
+		memset(dp,0x3f,sizeof(dp));
+		dp[0]=0;
+		scanf("%d%d",&n,&m);
+		for(int i=1;i<=n;i++) scanf("%lf%lf",x+i,y+i);
+		for(int i=1;i<=n;i++)
+			for(int j=1;j<=n;j++)
+			{
+				if(fabs(x[i]-x[j])<eps) continue;
+				double a,b;
+				cal(a,b,x[i]*x[i],x[i],y[i],x[j]*x[j],x[j],y[j]);
+				if(a>-eps) continue;
+				for(int k=1;k<=n;k++)
+					if(fabs(a*x[k]*x[k]+b*x[k]-y[k])<eps)
+						lines[i][j]|=(1<<(k-1));
+			}
+		for(int i=0;i<(1<<n);i++)
+		{
+			int j=must[i];
+			dp[i|(1<<(j-1))]=min(dp[i|(1<<(j-1))],dp[i]+1);
+			for(int k=1;k<=n;k++) dp[i|lines[j][k]]=min(dp[i|lines[j][k]],dp[i]+1);
+		}
+		printf("%d\n",dp[(1<<n)-1]);
+	}
+	return 0; 
+}