> ## 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.

# Find First and Last Position of Element in

> Tested Python solution for LeetCode 34 with 20 pytest cases. Generate a practice environment with lcpy.

LeetCode 34, Medium. Topics: Array, Binary Search. [View on LeetCode](https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array/description/).

Generate this problem as a practice environment: tested reference solution, 20 [parametrized pytest cases](/practice/testing), and a playground notebook:

```bash theme={"theme":{"light":"github-light","dark":"github-dark"}}
lcpy gen -n 34   # by problem number
lcpy gen -s find_first_and_last_position_of_element_in_sorted_array   # by problem name
```

## Problem

Given an array of integers `nums` sorted in non-decreasing order, find the starting and ending position of a given `target` value.

If `target` is not found in the array, return `[-1, -1]`.

You must write an algorithm with `O(log n)` runtime complexity.

### Examples

```
Input: nums = [5,7,7,8,8,10], target = 8
Output: [3,4]
```

```
Input: nums = [5,7,7,8,8,10], target = 6
Output: [-1,-1]
```

```
Input: nums = [], target = 0
Output: [-1,-1]
```

### Constraints

* `0 <= nums.length <= 10^5`
* `-10^9 <= nums[i] <= 10^9`
* `nums` is a non-decreasing array.
* `-10^9 <= target <= 10^9`

## Solution

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

```python theme={"theme":{"light":"github-light","dark":"github-dark"}}
class Solution:
    # Time: O(log n)
    # Space: O(1)
    def search_range(self, nums: list[int], target: int) -> list[int]:
        def find_left(nums: list[int], target: int) -> int:
            left, right = 0, len(nums) - 1
            while left <= right:
                mid = (left + right) // 2
                if nums[mid] < target:
                    left = mid + 1
                else:
                    right = mid - 1
            return left if left < len(nums) and nums[left] == target else -1

        def find_right(nums: list[int], target: int) -> int:
            left, right = 0, len(nums) - 1
            while left <= right:
                mid = (left + right) // 2
                if nums[mid] <= target:
                    left = mid + 1
                else:
                    right = mid - 1
            return right if right >= 0 and nums[right] == target else -1

        if not nums:
            return [-1, -1]

        left_pos = find_left(nums, target)
        if left_pos == -1:
            return [-1, -1]

        right_pos = find_right(nums, target)
        return [left_pos, right_pos]
```

## Complexity

| Time     | Space |
| -------- | ----- |
| O(log n) | O(1)  |

## Tags

[NeetCode All](/catalog/neetcode), [AlgoMaster 75](/catalog/algo-master-75).