Solution.java

class Solution {
    public int maxPoints(Point[] points) {
        if( points.length <= 2 ) return points.length;
        int max = 2 ;
        for( int i = 0 ; i < points.length ; i++ ){
            int samePosition = 0;
            int sameSlope = 1;
            for( int j = i + 1 ; j < points.length ; j++ ){
                long x1 = points[j].x - points[i].x;
                long y1 = points[j].y - points[i].y;
                if( x1 == 0 && y1 == 0 ){
                    samePosition++;
                } else {
                    sameSlope++;
                    for(int k = j + 1 ; k < points.length ; k++ ){
                        long x2 = points[k].x - points[i].x;
                        long y2 = points[k].y - points[i].y;
                        if ( x1 * y2 == x2 * y1 ) sameSlope++;
                    }
                }
                if(max < (samePosition + sameSlope)) max = samePosition + sameSlope;
                sameSlope = 1;
            }
        }
        return max;
    }
}