MergeInternvals.java

import java.util.*;

public class MergeInternvals {
 public int[][] merge(int[][] intervals) {
 if (intervals.length <= 1) {
 return intervals;
 }
 Arrays.sort(intervals, (a, b) -> Integer.compare(a[0], b[0]));
 int start = intervals[0][0];
 int end = intervals[0][1];

 List<int[]> list = new ArrayList<>();

 for (int i = 1; i < intervals.length; i++) {
 int first = intervals[i][0];
 int second = intervals[i][1];

 if (first <= end) {
 start = Math.min(start, first);
 end = Math.max(end, second);
 } else {
 int[] temp = new int[] { start, end };
 list.add(temp);
 start = first;
 end = second;
 }
 }
 int[] temp = new int[] { start, end };
 list.add(temp);

 return list.toArray(new int[list.size()][]);
 }

 public static void main(String[] args){
 int[][] intervals ={{1,3},{2,6},{8,10},{15,18}};
 MergeInternvals obj = new MergeInternvals();
 int[][] newIntervals = obj.merge(intervals);
 for(int i = 0; i < newIntervals.length; i++){
 for(int j = 0; j < newIntervals[0].length; j++){
 System.out.print(newIntervals[i][j]+ "\t");
 }
 System.out.println();
 }
 }
}