【几何】poj1118Lining up

O(n*n*n)的枚举算法即可秒杀

#include<iostream>#include<algorithm>using namespace std;struct Point{int x,y;};Point point[1001];int main(){int n,a,b,counter,maximum;while(cin>>n&&n){maximum=-1;for(int i=0;i<n;i++)cin>>point[i].x>>point[i].y;for(int i=0;i<n;i++){for(int j=i+1;j<n;j++){counter=0;a=point[i].x-point[j].x;b=point[i].y-point[j].y;for(int k=j+1;k<n;k++){if((point[k].x-point[i].x)*b==(point[k].y-point[i].y)*a)counter++;}maximum=max(maximum,counter);}}cout<<maximum+2<<endl;}//system("pause");return 0;}