reg-validator.cpp

#include <cctype>
#include <cstring>
#include <iostream>

typedef int (*Validator)(int);

bool isValidRegistration(char reg[9]) {
	const Validator validators[9] = {isupper, isupper, isdigit, isdigit, isdigit, isdigit, isupper, isupper };
	const int len = strlen(reg);
	const Validator *check = len == 8 ? validators : validators + 1;
	for (int c = 0; c < len; c++) {
		if (!check[c](reg[c])) {
			return false;
		}
	}
	return true;
}


int main() {
	char reg[6][9] = {"C1234AB", "XY1111YX", "111145", "ABC34DEF", "ABCDEF", "C11D"};
	for (int c = 0; c < sizeof(reg) / sizeof(reg[0]); c++) {
		std::cout << reg[c] << " - " << isValidRegistration(reg[c]) << '\n';
	}
	return 0;
}