OJ-Problems-Source/HDOJ/4195_autoAC.cpp
2016-09-04 14:28:52 +08:00

47 lines
1.1 KiB
C++

#include<cstdio>
#include<cstring>
#include<iostream>
#include<cmath>
#define eps 1e-6
#define pi acos(-1)
using namespace std;
struct node
{
double x,y;
};
node p[4];
double getdis(node p1,node p2)
{
return sqrt((p1.x-p2.x)*(p1.x-p2.x)+(p1.y-p2.y)*(p1.y-p2.y));
}
double getang(double a,double b,double c)
{
double ang= (a*a+b*b-c*c)/(2*a*b);
return acos(ang);
}
int main()
{
char str[1000];
while(gets(str)&&strcmp(str,"END")!=0)
{
sscanf(str,"%lf%lf",&p[0].x,&p[0].y);
scanf("%lf%lf%lf%lf",&p[1].x,&p[1].y,&p[2].x,&p[2].y);
getchar();
double dis1=getdis(p[0],p[1]);
double dis2=getdis(p[1],p[2]);
double dis3=getdis(p[0],p[2]);
double ang1=getang(dis1,dis2,dis3);
double ang2=getang(dis2,dis3,dis1);
double ang3=getang(dis1,dis3,dis2);
for(int i=3; i<=1000; i++)
{
if(ang1*i/pi-(int)(ang1*i/pi+eps)<eps && ang2*i/pi-(int)(ang2*i/pi+eps)<eps && ang3*i/pi-(int)(ang3*i/pi+eps)<eps)
{
printf("%d\n",i);
break;
}
}
}
return 0;
}