[Leetcode] Max Points on a Line

Given n points on a 2D plane, find the maximum number of points that lie on the same straight line.

Solution:

/**
 * Definition for a point.
 * class Point {
 *     int x;
 *     int y;
 *     Point() { x = 0; y = 0; }
 *     Point(int a, int b) { x = a; y = b; }
 * }
 */
public class Solution {
    public int maxPoints(Point[] points) {
        
        if(points.length==1)
        return 1;
        
        HashMap<Double, Integer> hm=new HashMap<Double, Integer>();
        int result=0;
        
        for(int i=0;i<points.length-1;++i){
            int infinitePoint=0;
            int samePoint=1;
            for(int j=i+1;j<points.length;++j){
                if(points[i].x==points[j].x){
                    if(points[i].y==points[j].y){
                        samePoint++;
                    }else{
                        infinitePoint++;
                    }
                }else{
                    double k=(points[j].y==points[i].y)?0.0:(1.0*((points[j].y)-points[i].y))/((points[j].x)-points[i].x);
                    if(hm.containsKey(k)){
                        int count=hm.get(k);
                        hm.put(k, count+1);
                    }else{
                        hm.put(k, 1);
                    }
                }
            }
            for(Integer iter:hm.values()){
                if(iter+samePoint>result){
                    result=iter+samePoint;
                }
            }
            result=Math.max(result, infinitePoint+samePoint);
            hm.clear();
        }
        return result;
    }
}

Note:

真是被自己蠢哭了啊，以前遇到过的问题，该犯的错还是犯了。。。囧

注意要在每次循环后把map给清掉。