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.

import java.util.HashMap;
import java.util.Iterator;

public class Solution {
    public int maxPoints(Point[] points) {
        int maxNums = 0;
        HashMap<Float, Integer> kAndLineNum = new HashMap<Float, Integer>();
        kAndLineNum.put(Float.MAX_VALUE, 0);
        int duplicate = 1;
        
        for(int i = 0; i < points.length; i++){
            kAndLineNum.clear();
            duplicate = 1;
            kAndLineNum.put(Float.MAX_VALUE, 0);
            
            for(int j = 0; j < points.length; j++){
                if(i == j)                        //
                    continue;
                if(points[i].x == points[j].x && points[i].y == points[j].y){                //重复点
                    duplicate ++;
                    continue;
                }
                float k = 0;
                k = points[i].x == points[j].x ? Float.MAX_VALUE : (float)(points[i].y - points[j].y) / (points[i].x - points[j].x);    //计算斜率
                if(kAndLineNum.get(k) != null){                                                //和其他点在同一直线上
                    Integer tempLineNum = kAndLineNum.get(k);
                    tempLineNum ++;
                    kAndLineNum.put(k, tempLineNum);
                }//if
                else{                                                                        //和其他点不在同意直线上
                    kAndLineNum.put(k, 1);
                }//else
            }//for
            
            for(Iterator<Float> iterator = kAndLineNum.keySet().iterator(); iterator.hasNext();){
                Float kValue = iterator.next();
                int pointsNum = kAndLineNum.get(kValue);
                maxNums = maxNums > (pointsNum + duplicate) ? maxNums : (pointsNum + duplicate);
            }//for
        }//for
        
        return maxNums;
    }
}