匡子语

摘要： Implement strStr().Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.思路：注意，在for循环中条件有计算得到的负数时, ... 阅读全文

摘要： Roman to IntegerGiven a roman numeral, convert it to an integer.Input is guaranteed to be within the range from 1 to 3999.思路：首先要学一下罗马数字是怎么表示的，参见百度百科其实... 阅读全文