import java.awt.*;
import java.awt.event.*;
public class JiSuan extends Frame {
Button s[] = new Button[19];
TextField t = new TextField("", 20);
FlowLayout f1;
GridLayout f2, f3;
Panel p1, p2, p3;
double a = 0, b, c;
int n;
public JiSuan() {
super("计算器");
s[0] = new Button("7");
s[1] = new Button("8");
s[2] = new Button("9");
s[3] = new Button("/");
s[4] = new Button("4");
s[5] = new Button("5");
s[6] = new Button("6");
s[7] = new Button("*");
s[8] = new Button("1");
s[9] = new Button("2");
s[10] = new Button("3");
s[11] = new Button("-");
s[12] = new Button("0");
s[13] = new Button(".");
s[14] = new Button("+");
s[15] = new Button("=");
s[16] = new Button("C");
s[17] = new Button("清零");
s[18] = new Button("sqrt");
s[3].setForeground(Color.blue);
s[7].setForeground(Color.blue);
s[11].setForeground(Color.blue);
s[13].setForeground(Color.blue);
s[14].setForeground(Color.blue);
s[15].setForeground(Color.blue);
s[16].setForeground(Color.red);
s[17].setForeground(Color.red);
s[18].setForeground(Color.red);
f1 = new FlowLayout(FlowLayout.CENTER);
p1 = new Panel();
p1.setLayout(f1);
p1.add(s[17]);
p1.add(s[16]);
p1.add(s[18]);
p2 = new Panel();
f2 = new GridLayout(2, 2, 3, 3);
p2.setLayout(f2);
p2.add(t);
p2.add(p1);
p3 = new Panel();
f3 = new GridLayout(4, 4, 3, 3);
p3.setLayout(f3);