一行兩個(gè)整數(shù) n, k ,意義如題。
對(duì)于 30% 的數(shù)據(jù) 0 < k < n <= 5 對(duì)于 60% 的數(shù)據(jù) 0 < k < n <= 100 對(duì)于 100% 的數(shù)據(jù) 0 < k < n <= 100000
5 3
2