题解

直接上代码！

#include <iostream>
#include <cmath>
using namespace std;
int x[800],y[800];
int main(){
    int n,cnt = 0,mx = 1;
    cin >> n;
    for(int i = 1;i <= n;i++){
        cin >> x[i] >> y[i];
    }
    for(int i = 1;i <= n;i++){
        for(int j = i + 1;j <= n;j++){
            cnt = 2;
            for(int k = 1;k <= n;k++){
                if(k == i || k == j){
                    continue;
                }
                if((x[k]-x[i])*(y[k]-y[j]) == (y[k]-y[i])*(x[k]-x[j])){
                    cnt++;
                }
            }
            mx = max(mx,cnt);
        }
    }
    cout << mx;
    return 0;
}