> 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/0015-3sum.md).

# 0015. 3Sum

<https://leetcode.com/problems/3sum>

## Description

Given an integer array nums, return all the triplets `[nums[i], nums[j], nums[k]]` such that `i != j`, `i != k`, and `j != k`, and `nums[i] + nums[j] + nums[k] == 0`.

Notice that the solution set must not contain duplicate triplets.

**Example 1:**

```
**Input:** nums = [-1,0,1,2,-1,-4]
**Output:** [[-1,-1,2],[-1,0,1]]
```

**Example 2:**

```
**Input:** nums = []
**Output:** []
```

**Example 3:**

```
**Input:** nums = [0]
**Output:** []
```

**Constraints:**

* `0 <= nums.length <= 3000`
* `-105 <= nums[i] <= 105`

## ac

```java
```