minesweeper c++

/**
* MINESWEEPER V1.0
* AUTHOR: BARTEK FERENC
*
* MAP INFO:
*
* DATA IN ARRAY:
* S - SAFE
* M - MINE
* D - MINE + FLAG
* N - SAFE + FLAG
*
* USER SEES:
* O - OPENED
* X -UNOPENED
* F - FLAG
*
* COPYRIGHT (C) 2018 by BARTEK FERENC
* http://aveneid.esy.es
**/

    #include <iostream>
    #include <cstdlib>
    #include <ctime>

    using namespace std;
    int N;
    char ** tab;
    int findallclose(int x, int y,int dir);
    int main()
    {
        int mines=0,x,y,f,c=0,r;
        srand(time(NULL));
        do{
        cout<<"rozmiar planszy: ";
        cin>>N;
        cout<<endl;}while(N<4);

       tab = new char * [N];
       for (int i = 0; i<N; i++)
            tab[i] = new char [N];

        for(int i=0;i<N;i++)
            for(int j=0;j<N;j++){r=rand()%100;
                if(r>34&&r<76){tab[i][j]='M'; mines++;}//generowanie

                else
                    tab[i][j]='S';}
            for(int i=0;i<N;i++){ //wyswietlanie planszy
                for(int j=0;j<N;j++)cout<<tab[i][j]<<" ";cout<<endl;}
                cout<<endl<<endl;


          do{
              //system("cls");
               /*             for(int i=0;i<N;i++){ //wyswietlanie planszy
                for(int j=0;j<N;j++)cout<<tab[i][j]<<" ";cout<<endl;}
                cout<<endl<<endl;
*/

            for(int i=0;i<N;i++){ //wyswietlanie planszy
                for(int j=0;j<N;j++){
                    switch(tab[i][j]){
                        case 'O': cout<<"."; break;
                        case 'D':cout<<"F"; break;
                        case 'N': cout<<"F"; break;
                        default: cout<<"X"; break;
                    }
                    cout<<" ";}
                cout<<endl;
                }
            cout<<"x: y: ";
            cin>>y>>x; //podaj x y do odkrycia
            cout<<"flag? (0/1)";
            cin>>f;
            x--;y--;
            //zmiana planszy
            if(f){
                 if(tab[x][y]=='M') {tab[x][y]='D'; c++;}
            else if(tab[x][y]=='S') tab[x][y]='N';
            else if(tab[x][y]=='D') {tab[x][y]='M'; c--;}
            else if(tab[x][y]=='N') tab[x][y]='S';
            }
            else if(tab[x][y]=='D') continue;
            else if(tab[x][y]=='N') continue;
            else{
            if(tab[x][y]=='M'){ cout<<"BOOM!"; return 0;}
            if(tab[x][y]=='S'){
             tab[x][y]='O';
             findallclose(x,y,0); //sprawdz miny od podanego pounktu
            }}
            if(c==mines) break;
          }while(1);

        cout<<"WIN!";


        delete tab;
        return 0;
    }

    int findallclose(int x, int y,int dir){

       //prawo spawdza miny w prawo od punktu
       if(dir != 1)
       for(int i=x;i<N;i++){
            if(tab[i][y]=='S'){
                tab[i][y]='O';
                findallclose(i,y,1);}
            else if(tab[i][y]=='X') break;}

        //lewo spawdza miny w lewo od punktu
       if(dir != 2)
        for(int i=x;i>0;i--){
            if(tab[i][y]=='S'){
                tab[i][y]='O';
                findallclose(i,y,2);
            }
            else if(tab[i][y]=='X') break;}

       //gora spawdza miny do gory od punktu
       if(dir != 3)
        for(int j=y;j>0;j--){
            if(tab[x][j]=='S'){
                tab[x][j]='O';
                findallclose(x,j,3);}
            else if(tab[x][j]=='X') break;}
        //dol spawdza miny do dolu od punktu
        if(dir != 4)
        for(int j=y;j<N;j++){
            if(tab[x][j]=='S'){
                tab[x][j]='O';
                findallclose(x,j,4);}
            else if(tab[x][j]=='X') break;}
    }