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 two binary strings, return their sum (also a binary string).For example,a ="11"b ="1"Return"100".解法：从后往前对两个string相加即可。注意将char转换为int，注意进位，注意结果顺序。... 阅读全文