passwordValidator.cpp

#include <iostream>
#include <string>
#include "libs.h"
using namespace std;

int main() {

	string password;
	bool isValid;
	while (true) {
		int small = 0, capital = 0, num = 0;
		cout << "Enter the password: ";
		getline(cin, password);

		if (password == "")
			break;
		if (password.length() >= 6 && password.length() <= 20)
		{
			for (size_t i = 0; i < password.length(); i++)
			{

				if (password[i] >= 'A' && password[i] <= 'Z')
				{
					// Capital letter [A-Z]
					capital++;
				}
				else if (password[i] >= 'a' && password[i] <= 'z') {
					// Small number [a-z]
					small++;
				}
				else if (password[i] >= '0' && password[i] <= '9')
				{	// Numeral values
					num++;
				}
				if (small > 0 && capital > 0 && num > 0)
				{
					// Password is found to be valid. no need to continue the loop anymore. This can be an overhead
					// but is worth it as it saves much computation when it happens.
					break;
				}
			}
			

		}
		if (small > 0 && capital > 0 && num > 0)
		{
			// Password is valid
			cout << "Password is valid" << endl;
		}
		else
		{
			// Invalid password
			cout << "Password not valid" << endl;
		}
	}
	cin.ignore();
}