스택 (Stack) & 큐 (Queue)

1. MainActivity.class

package ...
 
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
 
import java.util.Stack;
import java.util.concurrent.ConcurrentLinkedQueue;
 
public class MainActivity extends AppCompatActivity {
    EditText editText;
    Button button;
    Button button2;
 
    Stack<Integer> stack = new Stack<Integer>();
    int count = 0;
 
    EditText editText2;
    Button button3;
    Button button4;
 
    ConcurrentLinkedQueue<Integer> queue = new ConcurrentLinkedQueue<>();
    int count2 = 0;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        editText = (EditText) findViewById(R.id.editText);
 
        button = (Button) findViewById(R.id.button);
        button2 = (Button) findViewById(R.id.button2);
 
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                stack.push(count);
                editText.setText("\n스택에 추가함: " + count);
 
                count++;
 
                editText.append("\n스택 : " + stack);
            }
        });
 
        button2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int outValue = stack.pop();
                editText.setText("\n스택에서 가져옴 : " + outValue);
 
                editText.append("\n스택 : " + stack);
            }
        });
 
        editText2 = (EditText) findViewById(R.id.editText2);
 
        button3 = (Button) findViewById(R.id.button3);
        button4 = (Button) findViewById(R.id.button4);
 
        button3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                queue.offer(count2);
                editText2.setText("\n큐에 추가함 : " + count2);
 
                count2++;
 
                editText2.append("\n큐 : " + queue);
            }
        });
 
        button4.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int outValue = queue.poll();
                editText2.setText("\n큐에서 가져옴 : " + outValue);
 
                editText2.append("\n큐 : " + queue);
            }
        });
    }
}
 

2. activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="org.androidtown.mystack.MainActivity">
 
    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="38dp"
        android:layout_marginStart="38dp"
        android:layout_marginTop="21dp"
        android:text="스택에 넣기" />
 
    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignTop="@+id/button"
        android:layout_marginLeft="25dp"
        android:layout_marginStart="25dp"
        android:layout_toEndOf="@+id/button"
        android:layout_toRightOf="@+id/button"
        android:text="스택에서 빼기" />
 
    <EditText
        android:id="@+id/editText"
        android:layout_width="wrap_content"
        android:layout_height="100dp"
        android:layout_marginTop="78dp"
        android:ems="10"
        android:inputType="textPersonName"
        android:text="스택"
        android:layout_below="@+id/button3"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true" />
 
    <EditText
        android:id="@+id/editText2"
        android:layout_width="wrap_content"
        android:layout_height="100dp"
        android:layout_marginTop="34dp"
        android:ems="10"
        android:inputType="textPersonName"
        android:text="큐"
        android:layout_below="@+id/editText"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true" />
 
    <Button
        android:id="@+id/button3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/button"
        android:layout_alignStart="@+id/button"
        android:layout_below="@+id/button"
        android:layout_marginTop="20dp"
        android:text="큐에 넣기" />
 
    <Button
        android:id="@+id/button4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/button2"
        android:layout_alignStart="@+id/button2"
        android:layout_alignTop="@+id/button3"
        android:text="큐에서 빼기"
        android:layout_alignRight="@+id/button2"
        android:layout_alignEnd="@+id/button2" />
</RelativeLayout>
 

3. Result