摘要：
`Math String` Description: Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. What is " Roman 阅读全文
摘要：
`String Two Pointers` Description: Implement strStr(). Returns the index of the first occurrence of needle in haystack, or 1 if needle is not part of 阅读全文