F. PolandBall and Gifts It's Christmas time! PolandBall and his friends will be giving themselves gifts. There are n Balls overall. Each Ball has someone for whom he should bring a present according to some permutation p, pi ≠ i for all i. Unfortun…
题目链接: F. PolandBall and Gifts time limit per test 1.5 seconds memory limit per test 256 megabytes input standard input output standard output It's Christmas time! PolandBall and his friends will be giving themselves gifts. There are n Balls overall.…