摘要：
The set[1,2,3,…,n]contains a total ofn! unique permutations.By listing and labeling all of the permutations in order,We get the following sequence (ie... 阅读全文
摘要：
Given a stringsconsists of upper/lower-case alphabets and empty space characters' ', return the length of last word in the string.If the last word doe... 阅读全文