#include <iostream>
#include <string>
#include <vector>
#include <iterator>
#include <chrono>
#include <set>
#include <sstream>
#include <cstdlib>
#include <algorithm>
#include <random>

const int defSize = 4;
const int minSize = 3;
const int maxSize = 6;

using namespace std;

int parseCmdLineArgs(int argc, char* argv[]);
vector<string> fillNumbers(int n);
void showHelp(int n);
string getUserNumber(const vector<string>& numbers);
void analyze(const string& compNumber, const string& userNumber, int& dig, int& pos);

int main(int argc, char* argv[]) {
	int n = parseCmdLineArgs(argc, argv);
	vector<string> numbers = fillNumbers(n);
	mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
	shuffle(begin(numbers), end(numbers), rnd);
	string compNumber = numbers.front();

	showHelp(n);

	int moves = 0;
	int dig = 0;
	int pos = 0;

	while (dig != n || pos != n) {
		string userNumber = getUserNumber(numbers);
		analyze(compNumber, userNumber, dig, pos);
		cout << "digits:    " << dig << endl;
		cout << "positions: " << pos << endl;
		++moves;
	}
	cout << "You are winner!!!" << endl;
	cout << "Your result is " << moves << (moves == 1 ? "move." : " moves.") << endl;
}

int parseCmdLineArgs(int argc, char* argv[]) {
	int res = defSize;
	if (argc == 2) {
		int t;
		istringstream sinp(argv[1]);
		if (sinp >> t && sinp.eof()) {
			t = abs(t);
			res = minSize <= t && t <= maxSize ? t : defSize;
		}
	}
	return res;
}

vector<string> fillNumbers(int n) {
	vector<int> lowBounds = {102, 1023, 10234, 102345};
	vector<int> uppBounds = {987, 9876, 98765, 987654};
	vector<string> res;
	for (int i = lowBounds[n - minSize]; i <= uppBounds[n - minSize]; i++) {
		string t = to_string(i);
		set<char> s(t.begin(), t.end());
		if (s.size() == n) {
			res.push_back(t);
		}
	}
	return res;
}

void showHelp(int n) {
	cout  << "------------------------BULLS AND COWS-----------------------------------\n"
         << "Computer chose " << n << "-digit number without repeating digits.        \n"
         << "Your goal is to guess it. After each try computer shows 2 numbers:       \n"
         << "Digits   : <how many digits you guessed>                                 \n"
         << "Positions: <how many of them are in correct place>                       \n"
         << "Good luck!                                                               \n"
         << "-------------------------------------------------------------------------\n";
}

string getUserNumber(const vector<string>& numbers) {
	for (;;) {
		cout << "your guess: ";
		string line;
		getline(cin, line);
		istringstream sinp(line);
		int t;
		char c;
		if (sinp >> t && !(sinp >> c)) {
			string res = to_string(t);
			if (find(begin(numbers), end(numbers), res) != end(numbers)) {
				return res;
			}
		}
		cout << "Incorrect number. Try again..." << endl;
	}
}

void analyze(const string& compNumber, const string& userNumber, int& dig, int& pos) {
	dig = 0;
	pos = 0;
	for (int i = 0; i < int(userNumber.size()); i++) {
		for (int j = 0; j < int(compNumber.size()); j++) {
			if (userNumber[i] == compNumber[j]) {
				++dig;
				pos += i== j;
			}
		}
	}
}