HDU 6857 Clockwise or Counterclockwise
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; }