#include <iostream>
#include <regex>
#include <string>
/*
^(0[1-9]|[12][0-9]|3[01]) → Matches day (01–31).
/(0[1-9]|1[0-2]) → Matches month (01–12).
/\d{4}$ → Matches year (4 digits).
*/
int main() {
std::regex date_pattern(R"(^(0[1-9]|[12][0-9]|3[01])/(0[1-9]|1[0-2])/\d{4}$)");
// DD/MM/YYYY
std::string date = "03/05/2025";
if (std::regex_match(date, date_pattern)) {
std::cout << "Valid date format!" << std::endl;
} else {
std::cout << "Invalid date format!" << std::endl;
}
// DD/MM/YYYY
date = "03/14/2025";
if (std::regex_match(date, date_pattern)) {
std::cout << "Valid date format!" << std::endl;
} else {
std::cout << "Invalid date format!" << std::endl;
}
}
/*
run:
Valid date format!
Invalid date format!
*/
