HDU 6857 Clockwise or Counterclockwise
思路:
简单计算一下行列式即可
x1 y1 1
x2 y2 1
x3 y3 1
结果如果
大于0,就是逆时针
小于0,就是顺时针
#include<bits/stdc++.h>
#define mem(a) memset(a,0,sizeof(a))
#define forn(i,n) for(int i=0;i<n;++i)
#define for1(i,n) for(int i=1;i<=n;++i)
#define IO std::ios::sync_with_stdio(false); std::cin.tie(0)
#define ll long long
#define inf 0x3f3f3f3f
using namespace std;
const int maxn=1e7+50;
const int mod=1e9+7;
int main()
{
IO;
int T;
cin>>T;
while(T--)
{
ll x1,x2,x3,y1,y2,y3;
cin>>x1>>y1>>x2>>y2>>x3>>y3;
ll ans=(x1-x3)*y2+(x3-x2)*y1+(x2-x1)*y3;
if(ans>0)
cout<<"Counterclockwise\n";
else
cout<<"Clockwise\n";
}
return 0;
}