356. Line Reflection

    /*
     * 356. Line Reflection
     * 2016-7-13 by Mingyang
     */
     public boolean isReflected(int[][] points) {
            int max = Integer.MIN_VALUE;
            int min = Integer.MAX_VALUE;
            HashSet<String> set = new HashSet<>();
            for(int[] p:points){
                max = Math.max(max,p[0]);
                min = Math.min(min,p[0]);
                String str = p[0] + "a" + p[1];
                set.add(str);
            }
            int sum = max+min;
            for(int[] p:points){
                //int[] arr = {sum-p[0],p[1]};
                String str = (sum-p[0]) + "a" + p[1];
                if( !set.contains(str))
                    return false;
                
            }
            return true;
        }