> For the complete documentation index, see [llms.txt](https://jaywin.gitbook.io/leetcode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://jaywin.gitbook.io/leetcode/solutions/0057-insert-interval.md).

# 0057. Insert Interval

<https://leetcode.com/problems/insert-interval>

## Description

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].
```

**Example 3:**

```
**Input:** intervals = [], newInterval = [5,7]
**Output:** [[5,7]]
```

**Example 4:**

```
**Input:** intervals = [[1,5]], newInterval = [2,3]
**Output:** [[1,5]]
```

**Example 5:**

```
**Input:** intervals = [[1,5]], newInterval = [2,7]
**Output:** [[1,7]]
```

**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`

## ac

```java
/**
 * 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; }
 * }
 */
class Solution {
    public List<Interval> insert(List<Interval> intervals, Interval newInterval) {
        List<Interval> res = new ArrayList<Interval>();
        // edge cases
        if (intervals == null || newInterval == null) return res;

        // iterate list
        int start = newInterval.start, end = newInterval.end;
        int i = 0;
        for (; i < intervals.size(); i++) {
            Interval curr = intervals.get(i);
            if (curr.end < start) {  // won't cover this interval, skip
                res.add(curr);
            } else if (curr.start > end) {  // merge complete
                break;
            } else {
                start = Math.min(start, curr.start);
                end = Math.max(end, curr.end);
            }
        }
        // new interval
        Interval insert = new Interval(start, end);
        res.add(insert);
        // add remaining
        for (; i < intervals.size(); i++) {  
            res.add(intervals.get(i));
        }

        return res;
    }
}
```