> For the complete documentation index, see [llms.txt](https://coding-9.gitbook.io/untitled/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://coding-9.gitbook.io/untitled/hash-and-map/1282.-group-the-people-given-the-group-size-they-belong-to.md).

# 1282. Group the People Given the Group Size They Belong To

## Problem Statement

<br>

There are `n` people that are split into some unknown number of groups. Each person is labeled with a **unique ID** from `0` to `n - 1`.

You are given an integer array `groupSizes`, where `groupSizes[i]` is the size of the group that person `i` is in. For example, if `groupSizes[1] = 3`, then person `1` must be in a group of size `3`.

Return *a list of groups such that each person `i` is in a group of size `groupSizes[i]`*.

Each person should appear in **exactly one group**, and every person must be in a group. If there are multiple answers, **return any of them**. It is **guaranteed** that there will be **at least one** valid solution for the given input.

&#x20;

**Example 1:**

<pre><code><strong>Input: groupSizes = [3,3,3,3,3,1,3]
</strong><strong>Output: [[5],[0,1,2],[3,4,6]]
</strong>Explanation: 
The first group is [5]. The size is 1, and groupSizes[5] = 1.
The second group is [0,1,2]. The size is 3, and groupSizes[0] = groupSizes[1] = groupSizes[2] = 3.
The third group is [3,4,6]. The size is 3, and groupSizes[3] = groupSizes[4] = groupSizes[6] = 3.
Other possible solutions are [[2,1,6],[5],[0,4,3]] and [[5],[0,6,2],[4,3,1]].
</code></pre>

**Example 2:**

<pre><code><strong>Input: groupSizes = [2,1,3,3,3,2]
</strong><strong>Output: [[1],[0,5],[2,3,4]]
</strong></code></pre>

&#x20;

**Constraints:**

* `groupSizes.length == n`
* `1 <= n <= 500`
* `1 <= groupSizes[i] <= n`

## Intuition

```
Make a map and store the vector
```

### Links

<https://leetcode.com/problems/group-the-people-given-the-group-size-they-belong-to/description/?envType=daily-question&envId=2023-09-11>

### Video Links

### Approach 1:

```
```

{% code title="C++" lineNumbers="true" %}

```cpp
class Solution {
public:
    vector<vector<int>> groupThePeople(vector<int>& arr) {
        map<int, vector<int>> mp;
        vector<vector<int>> ans;

        for(int i=0; i<arr.size(); i++){
            int group_size = arr[i];
            mp[group_size].push_back(i);

            if(mp[group_size].size() == group_size){
                ans.push_back(mp[group_size]);
                mp.erase(group_size);
            }
        }

        return ans;
    }
};
```

{% endcode %}

### Approach 2:

```
```

{% code title="C++" lineNumbers="true" %}

```cpp
```

{% endcode %}

### Approach 3:

```
```

{% code title="C++" lineNumbers="true" %}

```cpp
```

{% endcode %}

### Approach 4:

```
```

{% code title="C++" lineNumbers="true" %}

```cpp
```

{% endcode %}

### Similar Problems

###