main.xml
<Button android:id="@+id/MainButton1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" android:text="OK"
android:layout_x="10px" android:layout_y="102px">
</Button>
<Button android:id="@+id/MainButton2"
android:layout_width="wrap_content"
android:layout_height="wrap_content" android:text="Cancel"
android:layout_x="80px" android:layout_y="102px">
</Button>
queen.xml:
<Button android:id="@+id/QueenButton1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" android:text="OK"
android:layout_gravity="right">
</Button>
MainActivity.java
package csu.android.applications;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.text.method.*;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity {
private EditText myEText;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);
myEText = (EditText) findViewById(R.id.MainEditText1);
myEText.setInputMethod(DigitsInputMethod.getInstance());
Button okButton = (Button) findViewById(R.id.MainButton1);
Button cancelButton = (Button) findViewById(R.id.MainButton2);
okButton.setOnClickListener(mOKListener);
cancelButton.setOnClickListener(mCancelListener);
}
private OnClickListener mOKListener = new OnClickListener() {
public void onClick(View v) {
String tmp = myEText.getText().toString();
if (!myEText.getText().toString().equals("")) {
int Qnum = Integer.parseInt(tmp);
if (Qnum <= 9) {
// Here we start up the main entry point
Intent intent = new Intent(MainActivity.this, Queen.class);
intent.putExtra("NumKey", tmp);
startActivity(intent);
finish();
} else {
showAlert("The number is bigger than 9!", 0, "Try again!",
"OK", true);
myEText.setText("");
return;
}
}
}
};
private OnClickListener mCancelListener = new OnClickListener() {
public void onClick(View v) {
myEText.setText("");
}
};
}
Queen.java
package csu.android.applications;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import java.util.*;
public class Queen extends Activity {
EditText myEText;
int QueenNum;
int totalcount = 0; // the total number of distinct results.
int uniquecount = 0; // the total number of unique results.
boolean[][] arr;
// Record the scores for mapping
ArrayList
// For check the duplicate solutions
int[][] arrRotation0;
int[][] arrRotation90;
int[][] arrRotation180;
int[][] arrRotation270;
int[][] arrMirror;
private StringBuilder sb;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.queen);
myEText = (EditText) findViewById(R.id.QueenEditText1);
Button backButton = (Button) findViewById(R.id.QueenButton1);
backButton.setOnClickListener(this.mBackListener);
Bundle extras = getIntent().getExtras();
if (extras != null) {
QueenNum = Integer.parseInt(extras.getString("NumKey"));
startCalculation();
myEText.setText(sb.toString());
} else {
showAlert("There is no input!", 0, "Click me", "OK", true);
Intent intent = new Intent(Queen.this, MainActivity.class);
startActivity(intent);
finish();
}
}
private OnClickListener mBackListener = new OnClickListener() {
public void onClick(View v) {
Intent intent = new Intent(Queen.this, MainActivity.class);
startActivity(intent);
finish();
}
};
/*
* startCalculation This method implements recursion for N*N Queen problem.
*/
public void startCalculation() {
sb = new StringBuilder();
// Array for N*N Queens problem
arr = new boolean[QueenNum][QueenNum];
// Array for calculating the duplicate result.
arrRotation0 = new int[QueenNum][QueenNum];
arrRotation90 = new int[QueenNum][QueenNum];
arrRotation180 = new int[QueenNum][QueenNum];
arrRotation270 = new int[QueenNum][QueenNum];
arrMirror = new int[QueenNum][QueenNum];
al = new ArrayList
// Prepare random numbers inserted into arrays
// for the calculation of the duplication .
prepareRotationData();
// Do recursions
putQtoArray(QueenNum - 1);
}
/*
* putQtoArray This method implements recursion for N*N Queen problem.
* @param: QueenNum
*/
public void putQtoArray(int myNum) {
if (myNum == -1) {
// Find a distinct result.
totalcount++;
// Display the result.
showMe();
return;
}
for (int i = 0; i <>
if (!checkRule(i, myNum)) {
arr[i][myNum] = true;
// Recursion
putQtoArray(myNum - 1);
arr[i][myNum] = false;
}
}
}
}
Because Activity "Queen" will be started by Activity "MainActivity" using Intent, we also need to add a line into AndroidManifest.xml as below, then that is all set. <activity android:name="Queen" android:label="@string/app_name">
