Given a set of intervals, for each of the interval i, check if there exists an interval j whose start point is bigger than or equal to the end point of the interval i, which can be called that j is on the "right" of i.

For any interval i, you need to store the minimum interval j's index, which means that the interval j has the minimum start point to build the "right" relationship for interval i. If the interval j doesn't exist, store -1 for the interval i. Finally, you need output the stored value of each interval as an array.

Note:

You may assume the interval's end point is always bigger than its start point.

You may assume none of these intervals have the same start point.

Example 1:

Input: [ [1,2] ]

Output: [-1]

Explanation: There is only one interval in the collection, so it outputs -1.

Example 2:

Input: [ [3,4], [2,3], [1,2] ]

Output: [-1, 0, 1]

Explanation: There is no satisfied "right" interval for [3,4].

For [2,3], the interval [3,4] has minimum-"right" start point;

For [1,2], the interval [2,3] has minimum-"right" start point.

Example 3:

Input: [ [1,4], [2,3], [3,4] ]

Output: [-1, 2, -1]

Explanation: There is no satisfied "right" interval for [1,4] and [3,4].

For [2,3], the interval [3,4] has minimum-"right" start point.

 /**

  * Definition for an interval.

  * public class Interval {

  *     int start;

  *     int end;

  *     Interval() { start = 0; end = 0; }

  *     Interval(int s, int e) { start = s; end = e; }

  * }

  */

 public class Solution {

     public int[] findRightInterval(Interval[] intervals) {

         if(intervals==null || intervals.length==0) return null;

         int[] res = new int[intervals.length];

         TreeMap<Integer, Integer> map = new TreeMap<Integer, Integer>();

         for (int i=0; i<intervals.length; i++) {

             map.put(intervals[i].start, i);

         }

         for (int i=0; i<intervals.length; i++) {

             Interval cur = intervals[i];

             Map.Entry<Integer, Integer> entry = map.higherEntry(cur.end-1);

             if (entry != null) {

                 res[i] = entry.getValue();

             }

             else res[i] = -1;

         }

         return res;

     }

 }