Wolverine TradingOA #1
Permutation Operations
估计中等可在线判题
You are given a permutation p of 1..n. Repeatedly perform the operation where item i of the new array takes item p[i] of the old array. Find the minimum number of operations needed for any array of distinct elements to return to its original state, modulo 10^9+7.
The constraints are complete; the direction in which the permutation is applied does not affect the cycle lengths or the answer.
This site adds the standard input/output protocol.
输入格式
The first line contains n (1 ≤ n ≤ 100000), and the second line contains the n numbers of p, a permutation of 1..n.
输出格式
Output the minimum positive number of operations needed to restore the original array, modulo 1000000007.
样例 1
输入:
3
2 1 3
输出:
2
样例 2
输入:
4
2 3 1 4
输出:
3
样例 3
输入:
5
2 1 4 5 3
输出:
6