Group the People Given the Group Size They Belong To

arrayhash tablegreedy

Problem Statement

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.

Examples

Example 1

Input: groupSizes = [3,3,3,3,3,1,3]
Output: [[5],[0,1,2],[3,4,6]]
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

🤔

Medium

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicHash Table