# Group the People Given the Group Size They Belong To

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

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.

### Example 1: ``` Input: groupSizes = [3,3,3,3,3,1,3] Output: [[5],[0,1,2],[3,4,6]] 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]]. ```

### Example 2: ``` Input: groupSizes = [2,1,3,3,3,2] Output: [[1],[0,5],[2,3,4]] ```

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

/** * @param {number[]} groupSizes * @return {number[][]} */ var groupThePeople = function(groupSizes) { const out = []; const map = new Map(); for (let i = 0; i < groupSizes.length; i++) { const groupSize = groupSizes[i]; const groupList = map.get(groupSize); (groupList) ? groupList.push(i) : map.set(groupSize, [i]); if (map.get(groupSize).length === groupSize) { out.push(map.get(groupSize)); map.delete(groupSize); } } return out; };