24. Insert Interval

Topic :

arrays

Difficulty :

medium

Problem Link :

problem statement

You are given an array of non-overlapping intervals intervals where intervals[i] = [starti, endi] represent the start and the end of the ith interval and intervals is sorted in ascending order by starti. You are also given an interval newInterval = [start, end] that represents the start and end of another interval.

Insert newInterval into intervals such that intervals is still sorted in ascending order by starti and intervals still does not have any overlapping intervals (merge overlapping intervals if necessary).

Return intervals after the insertion.

Example 1:

Input: intervals = [[1,3],[6,9]], newInterval = [2,5]
Output: [[1,5],[6,9]]

Example 2:

Input: intervals = [[1,2],[3,5],[6,7],[8,10],[12,16]], newInterval = [4,8]
Output: [[1,2],[3,10],[12,16]]
Explanation: Because the new interval [4,8] overlaps with [3,5],[6,7],[8,10].

Constraints:

0 <= intervals.length <= 104
intervals[i].length == 2
0 <= starti <= endi <= 105
intervals is sorted by starti in ascending order.
newInterval.length == 2
0 <= start <= end <= 105

solution

import java.io.*;
import java.util.*;
 class Insert_Interval
{
    static class Interval{
        int start;
        int end;
        Interval(int start, int end)
        {
            this.start=start;
            this.end=end;
        }
    }
    public static void main(String args[]){
      int[][]intervals = {{1,3},{6,9}}; int newInterval[] = {2,5};
      ArrayList<Interval> finalIntervals=new ArrayList<>();

      int[][] ans=insert(intervals,newInterval);
      
      for(int arr[]: ans){
        System.out.print(Arrays.toString(arr));
        }
    }
    static int[][] insert(int[][] intervals, int[] newInterval) {
       ArrayList<Interval> intervalList=new ArrayList<>();
       
        for (int[] interval: intervals){
          intervalList.add(new Interval(interval[0],interval[1]));
        }
        
        Interval toInsert=new Interval(newInterval[0],newInterval[1]);
        
        
        intervalList=insertAndMerge( intervalList,toInsert);
        
        int[][] ans=new int[intervalList.size()][2];
      
        for(int i=0;i<intervalList.size();i++){
            ans[i][0]=intervalList.get(i).start;
            ans[i][1]=intervalList.get(i).end;
            }

         return ans;
    }
    
    static ArrayList<Interval> insertAndMerge(ArrayList<Interval> intervals, Interval newInterval){
        Interval toInsert=newInterval;
        int i=0;
        
        while(i<intervals.size())
        {
            Interval curr=intervals.get(i);
            
            if(toInsert.start>curr.end) // if the interval to insert is
                i++;
            else if( toInsert.end<curr.start)
            {
              intervals.add(i,toInsert);
              break;
            }
            
            else {
                toInsert.start=Math.min( toInsert.start,curr.start);
                toInsert.end=Math.max(toInsert.end,curr.end);
                intervals.remove(i);
            }
        }
        
        if(i==intervals.size())
            intervals.add(toInsert);
        
        return intervals;
    }
}