Package g3501_3600.s3592_inverse_coin_change

Class Solution

java.lang.Object

g3501_3600.s3592_inverse_coin_change.Solution

public class Solution
extends Object

3592 - Inverse Coin Change.

Medium

You are given a 1-indexed integer array numWays, where numWays[i] represents the number of ways to select a total amount i using an infinite supply of some fixed coin denominations. Each denomination is a positive integer with value at most numWays.length.

However, the exact coin denominations have been lost. Your task is to recover the set of denominations that could have resulted in the given numWays array.

Return a sorted array containing unique integers which represents this set of denominations.

If no such set exists, return an empty array.

Example 1:

Input: numWays = [0,1,0,2,0,3,0,4,0,5]

Output: [2,4,6]

Explanation:

Amount	Number of ways	Explanation
1	0	There is no way to select coins with total value 1.
2	1	The only way is [2].
3	0	There is no way to select coins with total value 3.
4	2	The ways are [2, 2] and [4].
5	0	There is no way to select coins with total value 5.
6	3	The ways are [2, 2, 2], [2, 4], and [6].
7	0	There is no way to select coins with total value 7.
8	4	The ways are [2, 2, 2, 2], [2, 2, 4], [2, 6], and [4, 4].
9	0	There is no way to select coins with total value 9.
10	5	The ways are [2, 2, 2, 2, 2], [2, 2, 2, 4], [2, 4, 4], [2, 2, 6], and [4, 6].

Example 2:

Input: numWays = [1,2,2,3,4]

Output: [1,2,5]

Explanation:

Amount	Number of ways	Explanation
1	1	The only way is [1].
2	2	The ways are [1, 1] and [2].
3	2	The ways are [1, 1, 1] and [1, 2].
4	3	The ways are [1, 1, 1, 1], [1, 1, 2], and [2, 2].
5	4	The ways are [1, 1, 1, 1, 1], [1, 1, 1, 2], [1, 2, 2], and [5].

Example 3:

Input: numWays = [1,2,3,4,15]

Output: []

Explanation:

No set of denomination satisfies this array.

Constraints:

• 1 <= numWays.length <= 100
• 0 <= numWays[i] <= 2 * 108

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
List<Integer>	findCoins(int[] numWays)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Solution

public Solution()

Method Details

findCoins

public List<Integer> findCoins(int[] numWays)