This document contains the code for a Java program that allows a user to enter expressions using buttons for numbers and operators. It stores the expression elements in arrays and displays the expression and individual elements on the screen. When a button is pressed, the corresponding number or operator is added to the arrays and displayed. The paint method handles drawing the expression and elements on the screen.

1. EXPRESIONES REGULARES
Sosa Mejía anel verónica
21 DE SEPTIEMBRE DE 2016
ISC. ENRIQUE PONCE RIVERA
ITSP

2. import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.*;
public class Programa extends Applet {
Button b1, b2, b3, b4, b5, b6;
Label l1, l2;
int x = 200, y;
int xf, yf;
int xi = 200, yi;
int p = -1;
int v, z, m, k;
String a [] = new String[20];
int f[] = new int[20];
String pantalla[]=new String [20];
int cont = 0;
int n, r, l, q;
public void init() {
b1 = new Button("0");
b2 = new Button("1");
b3 = new Button("0*");
b4 = new Button("1*");
b5 = new Button("+");
b6 = new Button("borrar");

3. add(b1);
add(b2);
add(b3);
add(b4);
add(b5);
add(b6);
}
public boolean action(Event evt, Object Obj) {
if (evt.target.equals(b1)) {
f[cont] = 1;
a [cont] = "O";
pantalla[cont]="0";
cont++;
p++;
}
if (evt.target.equals(b2)) {
f[cont] = 2;
a [cont] = "1";
pantalla[cont]="1";

4. cont++;
p++;
}
if (evt.target.equals(b3)) {
f[cont] = 3;
ar[cont] = "0";
pantalla[cont]="0*";
cont++;
p++;
}
if (evt.target.equals(b4)) {
f[cont] = 4;
a[cont] = "1";
pantalla[cont]="1*";
cont++;
p++;

5. }
repaint();
System.out.println(cont);
return true;
}
public void paint(Graphics g) {
g.setColor(Color.GREEN);
g.fillRect(0, 0, 1440, 800);
b1.setSize(70, 50);
b2.setSize(70, 50);
b3.setSize(70, 50);
b4.setSize(70, 50);
b5.setSize(70, 50);
b6.setSize(70, 50);
b1.setLocation(50, 50);
b2.setLocation(120, 50);
b3.setLocation(190, 50);
b4.setLocation(260, 50);
b5.setLocation(330, 50);

6. b6.setLocation(700, 50);
y = 300;
x = 220;
xi = 200;
l = y - 25;
r = 200 - 50;
m = 200;
int c=1000;
g.drawString("exprecion:", 930, 200);
for (int i = 0; i < cont; i++) {
if (f[i] == 1) {
g.setColor(Color.BLACK);
xf = xi + 50;
g.drawLine(xi, y, xf, y);
xi = xf + 150;
g.drawOval(r, l, 50, 50);
r = r + 100;
g.drawOval(r, l, 50, 50);
r = r + 100;
g.drawString("" + a[i], x, y - 10);

7. x = x + 200;
g.drawString(""+pantalla[i], c, 200);
c+=10; }
if (f[i] == 2) {
g.setColor(Color.BLUE);
xf = xi + 50;
g.drawLine(xi, y, xf, y);
xi = xf + 150;
g.drawOval(r, l, 50, 50);
r = r + 100;
g.drawOval(r, l, 50, 50);
r = r + 100;
g.drawString("" + a[i], x, y - 10);
x = x + 200;
g.drawString(""+pantalla[i], c, 200);
c+=10;
}
if (f[i] == 3) {
g.setColor(Color.BLUE);
g.drawArc(x + 50, y - 50, 100, 50, 0, 180);

8. g.drawArc(x - 50, y - 50, 300, 150, 180, 180);
g.setColor(Color.BLUE);
xf = xi + 50;
g.drawLine(xi, y, xf, y);
xi = xf + 50;
xf = xi + 50;
g.drawLine(xi, y, xf, y);
xi = xf + 50;
xf = xi + 50;
g.drawLine(xi, y, xf, y);
xi = xf + 150;
g.drawOval(r, l, 50, 50);
r = r + 100;
g.drawOval(r, l, 50, 50);
r = r + 100;
g.drawOval(r, l, 50, 50);
r = r + 100;
g.drawOval(r, l, 50, 50);
r = r + 100;
g.drawString("" + a[i], x = xi - 275, y - 10);
x = x + 300;
g.drawString(""+pantalla[i], c, 200);
c+=10;
}

9. if (f[i] == 4) {
g.setColor(Color.BLUE);
g.drawArc(x + 50, y - 50, 100, 50, 0, 180);
g.drawArc(x - 50, y - 50, 300, 150, 180, 180);
g.setColor(Color.BLACK);
xf = xi + 50;
g.drawLine(xi, y, xf, y);
xi = xf + 50;
xf = xi + 50;
g.drawLine(xi, y, xf, y);
xi = xf + 50;
xf = xi + 50;
g.drawLine(xi, y, xf, y);
xi = xf + 150;
g.drawOval(r, l, 50, 50);
r = r + 100;
g.drawOval(r, l, 50, 50);
r = r + 100;
g.drawOval(r, l, 50, 50);
r = r + 100;
g.drawOval(r, l, 50, 50);
r = r + 100;
g.drawString("" + a[i], x = xi - 275, y - 10);
x = x + 300;

10. g.drawString(""+pantalla[i], c, 200);
c+=10;
}
if (f[i] == 5) {
v=xi; g.drawOval(xi - 50, y + 50, 50, 50);
g.drawOval(m - 150, y + 50, 50, 50);
x = 220;
xi = 200;
r = 200 - 50;
m = 200;
y = y + 150;
l = y - 25;
g.drawString(""+pantalla[i], c, 200);
c+=10;
}
}
y = 300;
xi = 100;
for (int i = 0; i < cont; i++) {
switch (f[i]) {

11. case 1:
g.setColor(Color.BLACK);
xf = xi + 50;
g.drawLine(xi, y, xf, y);
xi = xf + 150;
g.setColor(Color.BLACK);
g.fillRect(100, y, 50, 5);
break;
case 2:
g.setColor(Color.BLACK);
xf = xi + 50;
g.drawLine(xi, y, xf, y);
xi = xf + 150;
g.setColor(Color.BLACK);
g.fillRect(100, y, 50, 5);
break;
case 3:
g.setColor(Color.BLACK);
xf = xi + 50;
g.drawLine(xi, y, xf, y);
xi = xf + 50;
xf = xi + 50;
g.drawLine(xi, y, xf, y);

12. xi = xf + 50;
xf = xi + 50;
g.drawLine(xi, y, xf, y);
xi = xf + 150;
g.setColor(Color.BLACK);
g.fillRect(100, y, 50, 5);
break;
case 4:
g.setColor(Color.BLACK);
xf = xi + 50;
g.drawLine(xi, y, xf, y);
xi = xf + 50;
xf = xi + 50;
g.drawLine(xi, y, xf, y);
xi = xf + 50;
xf = xi + 50;
g.drawLine(xi, y, xf, y);
xi = xf + 150;
g.setColor(Color.BLACK);
g.fillRect(100, y, 50, 5);
break;
case 5:
v=xi;
x = 220;
xi = 100;

13. r = 200 - 50;
m = 200;
l = y - 25;
g.drawLine(xi+50, y, xi, y+75);
y = y + 150;
break;
case 7:
}
}
}
}