Insert Interval

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Problem

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].

Pseudocode

- if intervals overlap, merge them with [Math.min, Math.max]
- push intervals with smaller max values than merge min into left array
- push intervals wither larger min values than merge max into right array

Solution

var insert = function (intervals, newInterval) {
  // this is the trick, to split array to lesser or more than merge newInterval, then reconstitute result at the end
  let merge = [[], []];
  const result = [];

  for (let i = 0; i < intervals.length; i++) {
    let currInterval = intervals[i];
    const [lo, hi] = intervals[i];

    if (hi < newInterval[0]) {
      merge[0].push(currInterval);
    } else if (newInterval[1] < lo) {
      merge[1].push(currInterval);
    } else {
      // reassign newInterval with lowest and highest value if intervals overlap
      newInterval = [
        Math.min(newInterval[0], lo),
        Math.max(newInterval[1], hi),
      ];
    }
  }

  result.push(...merge[0], newInterval, ...merge[1]);
  return result;
};

Time and Space Complexity

Time

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Space

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