java 帮忙看看怎么弄

package cn.com.storm.common.test

import java.awt.BorderLayout

import java.awt.Color

import java.awt.GradientPaint

import java.awt.Graphics

import java.awt.Graphics2D

import java.awt.LayoutManager

import java.awt.Paint

import java.awt.event.ActionEvent

import java.awt.event.ActionListener

import java.util.Random

import javax.swing.JButton

import javax.swing.JFrame

import javax.swing.JOptionPane

import javax.swing.JPanel

import javax.swing.Timer

import javax.swing.UIManager

public class GradientPanel extends JPanel implements ActionListener {

/** 计时器 */

private Timer timer = null

private Color[] colors = new Color[] {Color.BLUE, Color.GREEN, Color.ORANGE, Color.RED, Color.YELLOW}

private Color nowColor = Color.RED

private JButton setTime = null

public GradientPanel(LayoutManager lm) {

super(lm)

setTime = new JButton("设置时间")

setTime.setActionCommand("setTime")

setTime.addActionListener(this)

timer = new Timer(1000, this)

timer.start()

}

public void paintComponent(Graphics g) {

super.paintComponent(g)

if (!isOpaque()) {

return

}

Color control = UIManager.getColor("control")

int width = getWidth()

int height = getHeight()

Graphics2D g2 = (Graphics2D) g

Paint storedPaint = g2.getPaint()

g2.setPaint(new GradientPaint(0, 0, nowColor, width, height, control))

g2.fillRect(0, 0, width, height)

g2.setPaint(storedPaint)

}

public static void main(String[] args) {

GradientPanel panel = new GradientPanel(new BorderLayout())

JFrame test = new JFrame()

test.getContentPane().add(panel, BorderLayout.CENTER)

test.getContentPane().add(panel.setTime, BorderLayout.NORTH)

test.setSize(500,300)

test.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE)

test.setVisible(true)

}

public void actionPerformed(ActionEvent e) {

String commond = e.getActionCommand()

if ("setTime".equals(commond)) {

this.timer.stop()

String result = JOptionPane.showInputDialog("请输入颜色变化的时间：")

if (result != null) {

double time = Double.valueOf(result).intValue()

timer.setDelay((int)(time * 1000))

}

this.timer.restart()

} else {

Random random = new Random()

int index = random.nextInt(colors.length)

nowColor = colors[index]

paintComponent(this.getGraphics())

}

}

}

看看这样达到要求了吗？建议自己看完代码后再自己写一遍，这是一个很好的学习过程。我也是边查API边做的。

代码写得比较乱。

好好的理解下，可以把它改的好些。

实际是采用搏唯递归法求扰宴解：基李培

a(n)=a(n-1)+a(n-3)

a(1)=1,a(2)=1,a(3)=2

我写一个简单的C程序，java程序很类似。

int f(int s)

{

if (s==1 || s==2) return 1

if (s==3) return 2

return f(s-1)+f(s-3)

}

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