三人木君

摘要： Problem E: Jolly JumpersA sequence of n > 0 integers is called a jolly jumper if the absolute values of the difference between successive elements take on all the values 1 through n-1. For instance,1 4 2 3is a jolly jumper, because the absolutes differences are 3, 2, and 1 respectively. The defin 阅读全文