Perfect Squares 2
Prereq: Knapsack Intro
This problem is similar to Perfect Squares, except a number can only be used once.
Again, we ask you to output the minimum number of numbers in order to sum to the desired number.
Output -1 if the number can't be reached.
Examples
Example 1:
Input: 12
Output: -1
Explanation:
You cannot make 12 with any combination of 1, 4, 9.
Example 2:
Input: 13
Output: 2
Explanation:
13 = 4 + 9