#include <iostream>
#include <cstdlib>
#include <string>
using namespace std;

int main(){

	int sudokuNumbers[9][9]{
		{2, 5, 1, 8, 6, 3, 9, 7, 4},
		{6, 3, 4, 2, 7, 9, 1, 5, 8},
		{8, 9, 7, 4, 1, 5, 3, 6, 2},
		{3, 1, 8, 6, 5, 2, 7, 4, 9},
		{7, 4, 6, 1, 9, 8, 2, 3, 5},
		{9, 2, 5, 3, 4, 7, 6, 8, 1},
		{1, 7, 9, 5, 3, 4, 8, 2, 6},
		{5, 8, 3, 9, 2, 6, 4, 1, 7},
		{4, 6, 2, 7, 8, 1, 5, 9, 3}
	};
	bool guessed[9][9]{
		{false, false, false, false, false, false, false, false, false,},
		{true, false, false, false, false, true, true, false, false},
		{false, false, true, false, false, true, false, false, true},
		{false, false, true, false, false, true, false, false, true},
		{false, false, true, false, true, false, false, true, false},
		{false, false, false, true, true, false, false, false, false},
		{true, false, false, true, false, true, false, true, false},
		{true, false, false, false, false, true, false, false, true},
		{true, false, false, false, false, false, false, false,true}
	};
	
	for(int i {0}; i < 9; i++){
	       for(int j {0}; j < 9; j++){
			if(guessed[i][j]){
		        	cout << sudokuNumbers[i][j];
			}
			else{
				cout << "-";
			}
			cout << " ";
	       }
	       cout <<"\n";
	}
	
	int row {0};
	int column {0};
	int guess {0};
	int allright {0};	
	while(allright != 81){
		cout << "What row is the number you want to guess?\n";
		cin >> row;
		if (!cin) {
			cerr << "Sorry, not a valid number.\n";
			return EXIT_FAILURE;
		}
		if (row > 9 || row < 1){
			cerr << "Sorry, that number is outside of the bounds of the game.\n";
			return EXIT_FAILURE;
		}

		cout << "What column is the number you want to guess?\n";
                cin >> column;
                if (!cin) {
                        cerr << "Sorry, not a valid number.\n";
                        return EXIT_FAILURE;
                }
                if (column > 9 || column < 1){
                        cerr << "Sorry, that number is outside of the bounds of the game.\n";
                        return EXIT_FAILURE;
                }

		cout << "What number would you like to guess?\n";
                cin >> guess;
                if (!cin) {
                        cerr << "Sorry, not a valid number.\n";
                        return EXIT_FAILURE;
                }
                if (guess > 9 || guess < 1){
                        cerr << "Sorry, that number is outside of the bounds of the game.\n";
                        return EXIT_FAILURE;
                }

		if(guess == sudokuNumbers[row-1][column-1]){
			guessed[row-1][column-1] = true;
			cout << "Great job! You guessed one of the numbers!\n";
		}
		else{
			cout << "That was not the right number. Try again.\n";
		}

		for(int i {0}; i < 9; i++){
                	for(int j {0}; j < 9; j++){
                        	if(guessed[i][j]){
                                	cout << sudokuNumbers[i][j];
                        	}
                        	else{
                                	cout << "-";
                        	}
                        	cout << " ";
               		}
               		cout <<"\n";
        	}
		for(int i {0}; i < 9; i++){
			for(int j {0}; j < 9; j++){
				if(guessed[i][j]){
					allright += 1;
				}
			}
		}
	}
		cout << "Congratulations, you solved a difficult one!";
		return EXIT_SUCCESS;
}