比赛 |
ZLXOI2015Day2 |
评测结果 |
AAAAAAAAAA |
题目名称 |
妹妹的饼干 |
最终得分 |
100 |
用户昵称 |
mikumikumi |
运行时间 |
0.004 s |
代码语言 |
C++ |
内存使用 |
0.33 MiB |
提交时间 |
2015-10-30 18:31:43 |
显示代码纯文本
#include<cstdio>
#include<iostream>
#include<cmath>
using namespace std;
typedef long long LL;
LL N;
class poi
{
public:
LL x,y;
}P[1100];
void read()
{
scanf("%lld",&N);
for(int i=1;i<=N;i++)
scanf("%lld%lld",&P[i].x,&P[i].y);
}
LL cross(poi a,poi b,poi c)
{
return (b.x-a.x)*(c.y-a.y)-(c.x-a.x)*(b.y-a.y);
}
LL area()
{
LL ans=0;
poi tem;
tem.x=tem.y=0;
for(int i=1;i<N;i++) ans+=cross(tem,P[i],P[i+1]);
ans+=cross(tem,P[N],P[1]);
ans=abs(ans);
return ans;
}
LL gcd(LL x,LL y)
{
if(y==0) return x;
return gcd(y,x%y);
}
LL POL()
{
LL ans=0;
int x,y;
for(int i=1;i<N;i++)
{
x=abs(P[i+1].x-P[i].x),y=abs(P[i+1].y-P[i].y);
ans+=gcd(x,y);
//cout<<ans<<endl;
}
x=abs(P[N].x-P[1].x),y=abs(P[N].y-P[1].y);
ans+=gcd(x,y);
return ans;
}
void work()
{
LL ans=0;
ans+=area();
ans-=POL();
ans+=2;
ans/=2;
printf("%lld",ans);
}
int main()
{
freopen("sistercookies.in","r",stdin);
freopen("sistercookies.out","w",stdout);
read();
work();
return 0;
}