> For the complete documentation index, see [llms.txt](https://mayanktyagi3111.gitbook.io/interview-prep/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mayanktyagi3111.gitbook.io/interview-prep/strings-arrays-and-2-pointers/merge-intervals.md).

# Merge Intervals

Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary).

*You may assume that the intervals were initially sorted according to their start times*.

**Example 1:**

Given intervals `[1,3],[6,9]` insert and merge `[2,5]` would result in `[1,5],[6,9]`.

**Example 2:**

Given `[1,2],[3,5],[6,7],[8,10],[12,16]`, insert and merge `[4,9]` would result in `[1,2],[3,10],[12,16]`.

This is because the new interval `[4,9]` overlaps with `[3,5],[6,7],[8,10]`.

Make sure the returned intervals are also sorted.

```java
public class Solution {
    public ArrayList<Interval> insert(ArrayList<Interval> intervals, Interval newInterval) {
        Interval current = newInterval;
        int i = 0;
        while (i < intervals.size()) {
            Interval in = intervals.get(i);
            if (in.end < current.start)
                i++;
            else if (in.start > current.end) {
                intervals.add(i, current);
                break;
            } else {
                current.start = Math.min(in.start, current.start);
                current.end = Math.max(in.end, current.end);
                intervals.remove(i);
            }
        }
        if (i == intervals.size()) 
            intervals.add(current);
        return intervals;
    }
}
```