> For the complete documentation index, see [llms.txt](https://anton-veselskyi.gitbook.io/codding-problems-solutions/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://anton-veselskyi.gitbook.io/codding-problems-solutions/leetcode/easy/contains-duplicate.md).

# Contains Duplicate

## [Contains Duplicate](https://leetcode.com/problems/contains-duplicate)

Given an array of integers, find if the array contains any duplicates.

Your function should return true if any value appears at least twice in the array, and it should return false if every element is distinct.

**Example 1:**

```

Input: [1,2,3,1]
Output: true
```

**Example 2:**

```

Input: [1,2,3,4]
Output: false
```

**Example 3:**

```

Input: [1,1,1,3,3,4,3,2,4,2]
Output: true
```

## Solutions

### 🧠 Cpp

```cpp
#include <algorithm>

class Solution {
public:
    bool containsDuplicate(vector<int> nums)
    {
        std::sort(nums.begin(), nums.end());

        if(
            nums.size()
            ==
            std::distance( nums.begin(), std::unique(nums.begin(), nums.end()) )
        )
            return false;
        else
            return true;
    }
};
```