NumbersPuzle, WellcomeActivity.java, 09.10.2021

package com.example.mynumberspuzzle;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;

import androidx.appcompat.app.AppCompatActivity;

public class WellcomeActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_wellcome);
    }

    public void startGame(View view) {
        int rows = 4;
        int cols = 4;

        switch (view.getId()) {
            case R.id.btnEasy:
                rows = 3;
                cols = 3;
                break;

            case R.id.btnMedium:
                rows = 4;
                cols = 4;
                break;

            case R.id.btnHard:
                rows = 5;
                cols = 5;
                break;
        }

        Intent intent = new Intent(this, MainActivity.class);
        intent.putExtra("ROWS_COUNT", rows);
        intent.putExtra("COLS_COUNT", cols);
        startActivity(intent);

    }
}