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9public class HelloWorld {
public static void main(String []args) {
System.out.println(" J A V V A ");
System.out.println(" J A A V V A A");
System.out.println("J J AAAAA V V AAAAA");
System.out.println(" JJ A A V A A");
}
}
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8public class HelloWorld {
public static void main(String []args) {
float pai;
pai=4*(1-1/3+1/5-1/7+1/9-1/11+1/13);
System.out.println("pai="+pai);
}
}
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public class A*B{
public static void main(String[] args) {
double a[3][3],b[3][3];
double [][] A={{a[0][0],a[0][1],a[0][2]}
{a[1][0],a[1][1],a[1][2]}
{a[2][0],a[2][1],a[2][2]}}
double [][] B={{b[0][0],b[0][1],b[0][2]}
{b[1][0],b[1][1],b[1][2]}
{b[2][0],b[2][1],b[2][2]}}
double [][] C={{c[0][0],c[0][1],c[0][2]}
{c[1][0],c[1][1],c[1][2]}
{c[2][0],c[2][1],c[2][2]}}
//输入
Scanner in=new Scanner(System in);
a[3][3]=scanner.nextLine();
b[3][3]=scanner.nextLine();
//计算
for(int i=0;i<3;i++){
for(int j=0;j<3;j++){
double m+=a[i][j]*b[j][i]
}
}
}
}
04 矩阵相乘算法1
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40public class ArrayMult {
public static void main(String[] args) {
int[][] a = {{1,2},{3,4},{5,6}};
int[][] b = {{1,2,3},{4,5,6}};
//m表示数组a的行数，n表示数组b的列数，s表示数组a的列数和数组b的行数
int m = a.length, n = b[0].length, s1 = a[0].length, s2 = b.length;
//判断两个数组是否能够相乘求积
if(s1 != s2) {
System.out.println("数组不能相乘，数组a的列数不等于数组b的行数");
return;
}
//动态创建数组c用来保存结果
int[][] c = new int[m][n];
for(int i=0; i<m; i++) //i表示数组c的每一行
for(int j=0; j<n; j++) { //j表示数组c的每一列
int temp = 0;
for(int k=0; k<s1; k++) //k表示数组a的列号和数组b的行号
temp+=a[i][k]*b[k][j];
c[i][j] = temp;
}
print(a);
print(b);
print(c);
}
private static void print(int[][] c) {
int m = c.length;
int n = c[0].length;
for(int i=0; i<m; i++) {
for(int j=0; j<n; j++) {
if(c[i][j]<10)
System.out.print(" ");
System.out.print(c[i][j] + " ");
}
System.out.println();
}
System.out.println("--------------------------------------");
}
}
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38import java.util.Scanner;
public class FingNearstPoints{
public static void main(String[] args) {
//输入
Scanner input=new Scanner(System in);
System.out.println("Enter the number of points:");
int numberOfPoints=intput.nextLine();
//
double[][] points=new double[numberOfPoints][2];
System.out.println("Enter"+numberOfPoints+"points");
for(int i=0;i<points.length;i++){
points[i][0]=input.nextDouble();
points[i][1]=input.nextDouble();
}
int p1=0,p2=1;
double shortDistance=distance(points[p1][0],points[p1][1],points[p2][0],points[p2][1]);
for(int i=0;i<points.length;i++){
for(int j=i+1;j<points.length;j++){
double distance=distance(points[i][0],points[i][10],points[j][0],points[j][10]);
if(shortDistance>distance){
p1=i;p2=j;
shortDistance=distance;
}
}
}
System.out.println("The two points are"+"("+points[p1][0]+","+points[p1][1]+")and("+points[p2][0]+","+points[p2][1]+")");
}
public static double distance (double x1,double y1,double x2,double y2)
{
return Math.sqrt(x2-x1)*(x2-x1)+(y2-y1)*(y2-y1);
}
}
}
03 日历 时钟
1 | package textchess; |
4 棋盘覆盖1
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226package textchess;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.print.attribute.standard.JobHoldUntil;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;
public class chessBoard extends JFrame {
private int tr, tc, dr, dc, size;//定义各成员变量
int tile = 1;
float red,green,blue;
JPanel centerPanel;
JPanel southPanel;
JButton[][] button;
JTextField TrText, TcText, DrText, DcText, SizeText;
JLabel TrLabel, TcLabel, DrLabel, DcLabel, SizeLabel;
JButton OKButton;
JButton CancelButton;
JPanel panel = new JPanel();
public chessBoard() {
super();
setTitle("棋盘覆盖");
this.setResizable(false);
centerPanel = new JPanel();
southPanel = new JPanel();
OKButton = new JButton("确定或开始");
OKButton.addActionListener(new OKButtonAction());
CancelButton = new JButton("取消或清除");
CancelButton.addActionListener(new OKButtonAction());
setBounds(300, -10, 900, 900);//设置窗口大小与位置
TrText = new JTextField("0",2);//定义各组件
TcText = new JTextField("0",2);
DrText = new JTextField("0",2);
DcText = new JTextField("0",2);
SizeText = new JTextField("4",2);
TrLabel = new JLabel("起始方格坐标x: ");
TcLabel = new JLabel("起始方格坐标y: ");
DrLabel = new JLabel("特殊方格坐标x: ");
DcLabel = new JLabel("特殊方格坐标y: ");
SizeLabel = new JLabel("棋盘规模size: ");
TrText.setEnabled(false);
TcText.setEnabled(false);
int tR = Integer.parseInt(TrText.getText());
int tC = Integer.parseInt(TcText.getText());
int dR = Integer.parseInt(DrText.getText());
int dC = Integer.parseInt(DcText.getText());
int Size = 1;
for (int i=0;i<Integer.parseInt(SizeText.getText());i++)
Size*=2;
tr = tR;
tc = tC;
dr = dR;
dc = dC;
size = Size;
southPanel.add(CancelButton);//添加各组件到窗体
southPanel.add(TrLabel);
southPanel.add(TrText);
southPanel.add(TcLabel);
southPanel.add(TcText);
southPanel.add(DrLabel);
southPanel.add(DrText);
southPanel.add(DcLabel);
southPanel.add(DcText);
southPanel.add(SizeLabel);
southPanel.add(SizeText);
southPanel.add(OKButton);
getContentPane().add(southPanel, BorderLayout.NORTH);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
class gridLayout {
public gridLayout() {
centerPanel.setLayout(new GridLayout(0, size));
button = new JButton[size][size];
for (int i = 0; i < size; i++) {
for (int j = 0; j < size; j++) {
button[i][j] = new JButton();
if (i == dr && j == dc) {
button[i][j].setBackground(Color.BLUE);
button[i][j].setText("<html><font size='3' color='white'>棋盘覆盖<br>Done By Java!</font></html>");
button[i][j].setEnabled(false);
}
centerPanel.add(button[i][j]);
}
}
}
private void sleep()
{
for (int i=0;i<100;i++)
for(int j=0;j<1000;j++);
}
public void ChessBoard(int tr, int tc, int dr, int dc, int size) {//算法实现
if (size == 1) // 棋盘方格大小为1,说明递归到最里层
return;
int t = tile++;// 每次递增1
Random rd = new Random();
red=rd.nextFloat();
green=rd.nextFloat();
blue=rd.nextFloat();
Color col = new Color(red,green,blue);
sleep();
int s = size / 2; // 棋盘中间的行、列号(相等的)
// 检查特殊方块是否在左上角子棋盘中
if (dr < tr + s && dc < tc + s) // 在
ChessBoard(tr, tc, dr, dc, s);
else // 不在，将该子棋盘右下角的方块视为特殊方块
{
button[tr + s - 1][tc + s - 1].setBackground(col);
button[tr + s - 1][tc + s - 1].setEnabled(false);
button[tr + s - 1][tc + s - 1].setText("<html><Font size='4',color='white'>"+t+"</Font></html>");
ChessBoard(tr, tc, tr + s - 1, tc + s - 1, s);
sleep();
}
// 检查特殊方块是否在右上角子棋盘中
if (dr < tr + s && dc >= tc + s) // 在
ChessBoard(tr, tc + s, dr, dc, s);
else // 不在，将该子棋盘左下角的方块视为特殊方块
{
button[tr + s - 1][tc + s].setBackground(col);
button[tr + s - 1][tc + s].setEnabled(false);
button[tr + s - 1][tc + s ].setText("<html><Font size='4',color='white'>"+t+"</Font></html>");
ChessBoard(tr, tc + s, tr + s - 1, tc + s, s);
sleep();
}
// 检查特殊方块是否在左下角子棋盘中
if (dr >= tr + s && dc < tc + s) // 在
ChessBoard(tr + s, tc, dr, dc, s);
else // 不在，将该子棋盘右上角的方块视为特殊方块
{
button[tr + s][tc + s - 1].setBackground(col);
button[tr + s][tc + s - 1].setEnabled(false);
button[tr + s ][tc + s - 1].setText("<html><Font size='4',color='white'>"+t+"</Font></html>");
ChessBoard(tr + s, tc, tr + s, tc + s - 1, s);
sleep();
}
// 检查特殊方块是否在右下角子棋盘中
if (dr >= tr + s && dc >= tc + s) // 在
ChessBoard(tr + s, tc + s, dr, dc, s);
else // 不在，将该子棋盘左上角的方块视为特殊方块
{
button[tr + s][tc + s].setBackground(col);
button[tr + s][tc + s].setEnabled(false);
button[tr + s ][tc + s ].setText("<html><Font size='4',color='white'>"+t+"</Font></html>");
ChessBoard(tr + s, tc + s, tr + s, tc + s, s);
sleep();
}
}
}
public class OKButtonAction implements ActionListener {//点下一个按钮时的事件响应
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
JButton whichButton = (JButton) e.getSource();//获取点击的事件，即是点下了哪个按钮
String whichName = whichButton.getActionCommand();
if(whichName.equals("确定或开始")) {
getContentPane().add(centerPanel, BorderLayout.CENTER);
int tR = Integer.parseInt(TrText.getText());
int tC = Integer.parseInt(TcText.getText());
int dR = Integer.parseInt(DrText.getText());
int dC = Integer.parseInt(DcText.getText());
int Size = 1;
for (int i=0;i<Integer.parseInt(SizeText.getText());i++)
Size*=2;
tr = tR;
tc = tC;
dr = dR;
dc = dC;
size = Size;
try {
gridLayout grid = new gridLayout();
grid.ChessBoard(tr, tc, dr, dc, size);
centerPanel.updateUI();
} catch (Exception EX) {
EX.printStackTrace();
}
panel.removeAll();
OKButton.setEnabled(false);
}
if (whichName.equals("取消或清除")) {//当你点下一个提示按钮时的事件响应
JLabel label = new JLabel();
label.setHorizontalAlignment(JLabel.CENTER);
label.setText("<html><Font size='+8',color='red'><center><b><br> 您取消了操作或是 <br><Font size='+8',color='blue'><center>您清除了前一个棋盘……" +
"<br><Font size='+8',color='green'><center>下面是关于题目的介绍<br><br><br><br><br><br> </b></Font></html>");
// JLabel l = new JLabel("题目要求");
JTextArea area = new JTextArea("在一个2k x 2k ( 即：2^k x 2^k )个方格组成的棋盘中，恰有一个方格与其他方格不同，" +
"称该方格为一特殊方格，且称该棋盘为一特殊棋盘。在棋盘覆盖问题中，要用4种不同形态的L型骨牌覆盖给定的特殊棋盘上除特殊方格以外的所有方格，" +
"且任何2个L型骨牌不得重叠覆盖。",7,60);
area.setLineWrap(true);
area.setBackground(Color.blue);
area.setForeground(Color.white);
area.setFont (new Font("SansSerif", Font.PLAIN, 14));
area.setEditable(false);
// FlowLayout layout = new FlowLayout();
// layout.addLayoutComponent(arg0, arg1)
panel.add(label,centerPanel );
// panel.add(l,southPanel);
panel.add(area,southPanel);
getContentPane().add(panel, BorderLayout.CENTER);
panel.updateUI();
tile=1;
centerPanel.removeAll();
OKButton.setEnabled(true);
}
}
}
public static void main(String[] args) {//主函数方法实现
chessBoard chess = new chessBoard();
chess.setVisible(true);
Runtime run = Runtime.getRuntime();
run.gc();//手动清除数据垃圾
}
}
