/**

// 耗时22ms

public int maxPoints2(Point[] points) {

if (points.length <= 0) {

return 0;

}

if (points.length <= 2) {

return points.length;

}

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

int result = 0;

for (int i = 0; i < points.length - 1; i++) {

map.clear();

int samep = 1, max = 0;

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

int deltaX = points[j].x - points[i].x;

int deltaY = points[j].y - points[i].y;

if (deltaX == 0 && deltaY == 0) {

samep++;

continue;

}

// 注意算斜率时可能出现k=0.0和-0.0的现象，两个是不一样的，所以这里对deltaY特殊处理

double k = deltaX == 0 ? Double.MAX_VALUE : deltaY == 0 ? 0 : (double) deltaY / deltaX;

if (map.containsKey(k)) {

map.put(k, map.get(k) + 1);

} else {

map.put(k, 1);

}

max = Math.max(max, map.get(k));

}

result = Math.max(result, max + samep);

}

return result;

}