> ## Documentation Index
> Fetch the complete documentation index at: https://leetcode-py.wisl.dev/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> leetcode-py is a Python LeetCode practice environment generator with one CLI: lcpy. It is not a service or platform.
> Each problem is a directory under leetcode/ with README.md, solution.py, test_solution.py, helpers.py, and playground.ipynb. lcpy gen creates them from JSON templates bundled with the package.
> Examples are backed by tests; copy them verbatim.

# Insert Interval Python Solution with Tests

> Tested Python solution for LeetCode 57 with 14 pytest cases. Generate a practice environment with lcpy.

LeetCode 57, Medium. Topics: Array. [View on LeetCode](https://leetcode.com/problems/insert-interval/description/).

Generate this problem as a practice environment: tested reference solution, 14 [parametrized pytest cases](/practice/testing), and a playground notebook:

```bash theme={"theme":{"light":"github-light","dark":"github-dark"}}
lcpy gen -n 57   # by problem number
lcpy gen -s insert_interval   # by problem name
```

## 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.

### Examples

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

```
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 \<= 10^4
* intervals\[i].length == 2
* 0 \<= starti \<= endi \<= 10^5
* intervals is sorted by starti in ascending order
* newInterval.length == 2
* 0 \<= start \<= end \<= 10^5

## Solution

Reference implementation from [solution.py on GitHub](https://github.com/wislertt/leetcode-py/blob/main/leetcode/insert_interval/solution.py), full suite in [test\_solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/insert_interval/test_solution.py):

```python theme={"theme":{"light":"github-light","dark":"github-dark"}}
class Solution:
    # Time: O(n)
    # Space: O(n)
    def insert(self, intervals: list[list[int]], new_interval: list[int]) -> list[list[int]]:
        result = []
        i = 0

        # Add intervals before new_interval
        while i < len(intervals) and intervals[i][1] < new_interval[0]:
            result.append(intervals[i])
            i += 1

        # Merge overlapping intervals
        while i < len(intervals) and intervals[i][0] <= new_interval[1]:
            new_interval[0] = min(new_interval[0], intervals[i][0])
            new_interval[1] = max(new_interval[1], intervals[i][1])
            i += 1
        result.append(new_interval)

        # Add remaining intervals
        result.extend(intervals[i:])
        return result
```

## Complexity

| Time | Space |
| ---- | ----- |
| O(n) | O(n)  |

## Tags

[Grind 75](/catalog/grind-75), [Grind](/catalog/grind), [Blind 75](/catalog/blind-75), [NeetCode 150](/catalog/neetcode-150), [NeetCode 250](/catalog/neetcode-250), [NeetCode All](/catalog/neetcode).