package leetcode;

 import java.util.HashMap;

 class Point{

     int x;

     int y;

     Point(){

         x=0;

         y=0;

     }

     Point(int a,int b){

         x=a;

         y=b;

     }

 }

 public class MaxPointOnALine {

     public static int maxPoints(Point[] points) {

         if(points.length<=2) {

             return points.length;

         }

         //斜率

         double k = 0.0;

         int maxPointNum      = 0;

         int parallelNum =0;

         int tempMaxPointNum  = 0;

         int sameNum=0;

         HashMap map=new HashMap<Double,Integer>();

         for(int i=0;i<points.length;i++){

             sameNum=1;

             parallelNum=0;

             tempMaxPointNum=0;

             map.clear();

             for(int j=i+1;j<points.length;j++){

                 if(points[i].x==points[j].x&&points[i].y==points[j].y){

                     sameNum++;

                 }

                 else if(points[i].x==points[j].x){

                     parallelNum++;

                 }else {

                     if(points[i].y==points[j].y){

                         k=0.0;

                     }else{

                         k=((double)(points[i].y-points[j].y))/(points[i].x-points[j].x);

                     }

                     if(map.get(k)==null){

                         map.put(k, new Integer(1));

                         if(1>tempMaxPointNum){

                             tempMaxPointNum=1;

                         }

                     }else{

                         int number=(int)map.get(k);

                         number++;

                         map.put(k, number);

                         if(number>tempMaxPointNum){

                             tempMaxPointNum=number;

                         }

                     }

                 }

             }

             if(parallelNum>1){

                 if(parallelNum>tempMaxPointNum)

                     tempMaxPointNum=parallelNum;

             }

             tempMaxPointNum+=sameNum;

             if(tempMaxPointNum>maxPointNum)

                 maxPointNum=tempMaxPointNum;

         }

         return maxPointNum;

     }

     public static void main(String[] args){

         Point[] parr = {new Point(1,1),new Point(1,2)};

         //maxPoints(parr);

         System.out.println(maxPoints(parr));

     }

 }