摘要： Given a string containing just the characters'(',')','{','}','['and']', determine if the input string is valid.The brackets must close in the correct ... 阅读全文

摘要： Given a linked list, remove thenthnode from the end of list and return its head.For example.Given linked list: 1->2->3->4->5, and n = 2.After removing... 阅读全文