#include <iostream>
#include <string>
#include "nQueens.h"

using std::string;
using std::cin;
using std::cout;
using std::cerr;
using std::endl;
using std::getline;

const int DEFAULT_N = 4;
const string DEFAULT_OUTPUT_FILENAME = "labBacktracking.txt";

int main( /*int argc, char* argv[] */){

    cout << "Please enter the number of queens (or simply press return to use " << DEFAULT_N << ")\n";

    int n = DEFAULT_N;
    // Attempt to read in the number of queens.
    // If just a return ('\n') was entered, use DEFAULT_N.  
    if( cin.peek() != '\n'){  // verify the next character is not a newline
        if( !(cin >> n)){     // check for invalid input
            cerr << "Invalid input for number of queens!\n";
            return 0;
        }
    }
    
    cin.ignore(); // clear out the '\n'

    // If just a return ('\n') is entered, then use DEFAULT_OUTPUT_FILENAME.
    // Otherwise, read in the output filename from STDIN.
    string outputFilename;
    cout << "Please enter the output filename (or simply press return to use " << DEFAULT_OUTPUT_FILENAME << ")\n";
    getline( cin, outputFilename);
    if( outputFilename == ""){
        outputFilename = DEFAULT_OUTPUT_FILENAME;
    }
    
    printNQueensSolution( n, outputFilename);
    
    return 0;
}