Problem Statement
Alice and Bob are playing a game called "The Permutation Game". The game is parameterized with the int N. At the start of the game, Alice chooses a positive integer x, and Bob chooses a permutation of the first N positive integers. Let p be Bob's permutation. Alice will start at 1, and apply the permutation to this value x times. More formally, let f(1) = p[1], and f(m) = p[f(m-1)] for all m >= 2. Alice's final value will be f(x). Alice wants to choose the smallest x such that f(x) = 1 for any permutation Bob can provide. Compute and return the value of such x.
Definition
- Class:
- ThePermutationGameDiv2
- Method:
- findMin
- Parameters:
- int
- Returns:
- long
- Method signature:
- long findMin(int N)
- (be sure your method is public)
Notes
- The return value will fit into a signed 64-bit integer.
- A permutation of the first N positive integers is a sequence of length N that contains each of the integers 1 through N exactly once. The i-th (1-indexed) element of a permutation p is denoted by p[i].
Constraints
- N will be between 1 and 35 inclusive.
Examples
2
Returns: 2
Bob can choose the permutations {1,2} or {2,1}. If Alice chooses 1, then, Bob can choose the permutation {2,1}, which would would make f(1) = 2. However, if Alice chooses 2, no matter which permutation Bob chooses, Alice will get f(2) = 1. Thus the answer in this case is 2.3
Returns: 6
6
Returns: 60
11
Returns: 27720
25
Returns: 26771144400