摘要：
Description Implement function ToLowerCase() that has a string parameter str, and returns the same string in lowercase. Example 1: Input: "Hello" Outp 阅读全文
摘要：
Description You're given strings J representing the types of stones that are jewels, and S representing the stones you have. Each character in S is a 阅读全文
摘要：
Builder pattern builds a complex object using simple objects and using a step by step approach. This type of design pattern comes under creational pat 阅读全文