James Pan

原题网址：https://leetcode.com/problems/string-to-integer-atoi/ Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. If you want a challenge, please

原题网址：https://leetcode.com/problems/regular-expression-matching/ Implement regular expression matching with support for '.' and '*'. '.' Matches any single character. '*' Matches zero or more of

原题网址：https://leetcode.com/problems/valid-number/ Validate if a given string is numeric. Some examples: "0" => true " 0.1 " => true "abc" => false "1 a" => false "2e10" => true Note: