40>longestDigitsPrefix

Given a string, output its longest prefix which contains only digits. Example For inputString="123aa1", the output should be longestDigitsPrefix(inputString) = "123".

code>>

std::string longestDigitsPrefix(std::string inputString) {

std::regex reg("^[0-9]+");

std::smatch m;

std::regex_search(inputString, m, reg);

return m.str();

}

regex_match 문자열 전체가 정확히 참

regex_search 문자열 중 있다면 참

다른 사람 풀이>>

std::string longestDigitsPrefix(std::string inputString) {

return inputString.substr(0, inputString.find_first_not_of("0123456789"));

}