# 11.09.2023 [1282. Group the People Given the Group Size They Belong To]
Groups from groups sizes array
11.09.2023
1282. Group the People Given the Group Size They Belong To medium
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Problem TLDR
Groups from groups sizes array
Intuition
First, group by sizes, next, chunk by groups size each.
Approach
Let’s write it using Kotlin collections API
Complexity
Time complexity:
O(n)Space complexity:
O(n)
Code
// 2 1 3 3 3 2 1 1 1 2 2
// 0 1 2 3 4 5 6 7 8 9 10
// 2 -> 0 5 [9 10]
// 1 -> 1 [6] [7] [8]
// 3 -> 2 3 4
fun groupThePeople(groupSizes: IntArray) =
groupSizes
.withIndex()
.groupBy { it.value }
.flatMap { (sz, nums) ->
nums.map { it.index }.chunked(sz)
}