冰点猎手

摘要： The set [1,2,3,…,n] contains a total of n! unique permutations.By listing and labeling all of the permutations in order,We get the following sequence (ie, for n = 3): "123" "132" "213" "231" "312" "321"Given n and k, return the kth permutat 阅读全文