1 import java.util.HashMap; 2 import java.util.Iterator; 3  4 public class Solution { 5     public int maxPoints(Point[] points) { 6         int maxNums = 0; 7         HashMap<Float, Integer> kAndLineNum = new HashMap<Float, Integer>(); 8         kAndLineNum.put(Float.MAX_VALUE, 0); 9         int duplicate = 1;10         11         for(int i = 0; i < points.length; i++){12             kAndLineNum.clear();13             duplicate = 1;14             kAndLineNum.put(Float.MAX_VALUE, 0);15             16             for(int j = 0; j < points.length; j++){17                 if(i == j)                        //18                     continue;19                 if(points[i].x == points[j].x && points[i].y == points[j].y){                //重复点20                     duplicate ++;21                     continue;22                 }23                 float k = 0;24                 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25                 if(kAndLineNum.get(k) != null){                                                //和其他点在同一直线上26                     Integer tempLineNum = kAndLineNum.get(k);27                     tempLineNum ++;28                     kAndLineNum.put(k, tempLineNum);29                 }//if30                 else{                                                                        //和其他点不在同意直线上31                     kAndLineNum.put(k, 1);32                 }//else33             }//for34             35             for(Iterator<Float> iterator = kAndLineNum.keySet().iterator(); iterator.hasNext();){36                 Float kValue =http://www.mamicode.com/ iterator.next();37                 int pointsNum = kAndLineNum.get(kValue);38                 maxNums = maxNums > (pointsNum + duplicate) ? maxNums : (pointsNum + duplicate);39             }//for40         }//for41         42         return maxNums;43     }44 }