We Keep Coding

Addition of two binary numbers

I tried to compere each number by putting the numbers in char arrays and compere them each by each with if conditions. Each outcome should be covered and each outcome should be saved in String result but the result of the whole operation is always blank. Java debugger isn't working and I don´t see why it isn't working.
import java.util.Scanner;
public class BinaryAdder {
public static String add(String binary1, String binary2) {
String result = "";
char[] safea = binary1.toCharArray();
char[] safeb = binary2.toCharArray();
int lb1 = binary1.length() - 1;
int lb2 = binary2.length() - 1;
char reminder = 0;
while (lb1 != 0 || lb2 != 0) {
if (safea[lb1] == 0 && safeb[lb2] == 0 && reminder == 0) {
result += "0";
lb1--;
lb2--;
} else if (safea[lb1] == 1 && safeb[lb2] == 0 && reminder == 0) {
result += "1";
lb1--;
lb2--;
} else if (safea[lb1] == 1 && safeb[lb2] == 1 && reminder == 0) {
result += "0";
reminder = 1;
lb1--;
lb2--;
} else if (safea[lb1] == 1 && safeb[lb2] == 1 && reminder == 1) {
result += "1";
reminder = 1;
lb1--;
lb2--;
} else if (safea[lb1] == 1 && safeb[lb2] == 0 && reminder == 1) {
result += "0";
reminder = 1;
lb1--;
lb2--;
} else if (safea[lb1] == 0 && safeb[lb2] == 1 && reminder == 1) {
result += "0";
reminder = 1;
lb1--;
lb2--;
} else if (safea[lb1] == 0 && safeb[lb2] == 1 && reminder == 0) {
result += "1";
lb1--;
lb2--;
} else if (safea[lb1] == 0 && safeb[lb2] == 0 && reminder == 1) {
result += "1";
lb1--;
lb2--;
}
}
return result;
}
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.print("Summand: ");
String input1 = scan.next("(0|1)*");
System.out.print("Summand: ");
String input2 = scan.next("(0|1)*");
scan.close();
System.out.println("Result: " + add(input1, input2));
}
}

You can parse the bits into integer with Integer.parseInt(s, radix). You need to use radix of 2:
public static String add(String binary1, String binary2) {
int i1 = Integer.parseInt(binary1, 2);
int i2 = Integer.parseInt(binary2, 2);
return Integer.toBinaryString(i1 + i2);
}

How to shorten block of code for bingo checker? (beginner question)

I'm making a checkwinner class that checks 4 arrays for a bingo win, and it is wayyyy too long. Any way i can shorten it? I know you can use a for loop, but I have no idea how.thank you in advance!
public static boolean checkWinner(String[][] card, String[][] card2, String[][] card3, String[][]card4) {
if ((card[0][0] == card[0][1] && card[0][1] == card[0][2] && card[0][2] == card[0][3] && card[0][3] == card[0][4]) || (card[1][0] == card[1][1] && card[1][1] == card[1][2] && card[1][2] == card[1][3] && card[1][3] == card[1][4])|| (card[2][0] == card[2][1] && card[2][1] == card[2][3] && card[2][3] == card[2][4]) || (card[3][0] == card[3][1] && card[3][1] == card[3][2] && card[3][2] == card[3][3] && card[3][3] == card[3][4])
|| (card[4][0] == card[4][1] && card[4][1] == card[4][2] && card[4][2] == card[4][3] && card[4][3] == card[4][4])) {
System.out.println("BINGO! Congratulations, you have won!");
displayBoard(card, card2, card3, card4);
System.exit(0);
return false;
} else if ((card[0][0] == card[1][0] && card[1][0] == card[2][0] && card[2][0] == card[3][0] && card[3][0] == card[4][0]) || (card[0][1] == card[1][1] && card[1][1] == card[2][1] && card[2][1] == card[3][1] && card[3][1] == card[4][1])
|| (card[0][2] == card[1][2] && card[1][2] == card[3][2] && card[3][2] == card[4][2]) || (card[0][3] == card[1][3] && card[1][3] == card[2][3] && card[2][3] == card[3][3] && card[3][3] == card[4][3])
|| (card[0][4] == card[1][4] && card[1][4] == card[2][4] && card[2][4] == card[3][4] && card[3][4] == card[4][4])) {
System.out.println("BINGO! Congratulations, you have won!");
displayBoard(card, card2, card3, card4);
System.exit(0);
return false;
} else if ((card[0][0] == card[1][1] && card[1][1] == card[3][3] && card[3][3]== card[4][4]) || (card[4][0] == card[3][1] && card[3][1] == card[1][3] && card[1][3]== card[0][4])) {
System.out.println("BINGO! Congratulations, you have won!");
displayBoard(card, card2, card3, card4);
System.exit(0);
return false;
} else if ((card2[0][0] == card2[0][1] && card2[0][1] == card2[0][2] && card2[0][2] == card2[0][3] && card2[0][3] == card2[0][4]) || (card2[1][0] == card2[1][1] && card2[1][1] == card2[1][2] && card2[1][2] == card2[1][3] && card2[1][3] == card2[1][4])
|| (card2[2][0] == card2[2][1] && card2[2][1] == card2[2][3] && card2[2][3] == card2[2][4]) || (card2[3][0] == card2[3][1] && card2[3][1] == card2[3][2] && card2[3][2] == card2[3][3] && card2[3][3] == card2[3][4])
|| (card2[4][0] == card2[4][1] && card2[4][1] == card2[4][2] && card2[4][2] == card2[4][3] && card2[4][3] == card2[4][4])) {
System.out.println("BINGO! Congratulations, you have won!");
displayBoard(card, card2, card3, card4);
System.exit(0);
return false;
} else if ((card2[0][0] == card2[1][0] && card2[1][0] == card2[2][0] && card2[2][0] == card2[3][0] && card2[3][0] == card2[4][0]) || (card2[0][1] == card2[1][1] && card2[1][1] == card2[2][1] && card2[2][1] == card2[3][1] && card2[3][1] == card2[4][1])
|| (card2[0][2] == card2[1][2] && card2[1][2] == card2[3][2] && card2[3][2] == card2[4][2]) || (card2[0][3] == card2[1][3] && card2[1][3] == card2[2][3] && card2[2][3] == card2[3][3] && card2[3][3] == card2[4][3])
|| (card2[0][4] == card2[1][4] && card2[1][4] == card2[2][4] && card2[2][4] == card2[3][4] && card2[3][4] == card2[4][4])) {
System.out.println("BINGO! Congratulations, you have won!");
displayBoard(card, card2, card3, card4);
System.exit(0);
return false;
} else if ((card2[0][0] == card2[1][1] && card2[1][1] == card2[3][3] && card2[3][3]== card2[4][4]) || (card2[4][0] == card2[3][1] && card2[3][1] == card2[1][3] && card2[1][3]== card2[0][4])) {
System.out.println("BINGO! Congratulations, you have won!");
displayBoard(card, card2, card3, card4);
System.exit(0);
return false;
} else if ((card3[0][0] == card3[0][1] && card3[0][1] == card3[0][2] && card3[0][2] == card3[0][3] && card3[0][3] == card3[0][4]) || (card3[1][0] == card3[1][1] && card3[1][1] == card3[1][2] && card3[1][2] == card3[1][3] && card3[1][3] == card3[1][4])|| (card3[2][0] == card3[2][1] && card3[2][1] == card3[2][3] && card3[2][3] == card3[2][4])
|| (card3[3][0] == card3[3][1] && card3[3][1] == card3[3][2] && card3[3][2] == card3[3][3] && card3[3][3] == card3[3][4])
|| (card3[4][0] == card3[4][1] && card3[4][1] == card3[4][2] && card3[4][2] == card3[4][3] && card3[4][3] == card3[4][4])) {
System.out.println("CPU CALLS BINGO! YOU LOSE!");
displayBoard(card, card2, card3, card4);
System.exit(0);
return false;
}
}
return true;
}

I think what you have written in the checkWinner method is quite short, because using loops will give make your code more tedious to work with and it will be a lot longer. But, I have written down the CheckWinner method using loops. I haven't ran this code in IDE. So, there maybe some bugs. I hope is helped you.
NOTE:below code is only implementing for the card method only
public static boolean checkWinner(String[][] card, String[][] card2, String[][] card3, String[][]card4) {
boolean flag = true;
//repeat this nested-loop for card2 and card3 similarly, which I haven't showed in my code.
//The below nested loop are for the condition for the 'if' condition in your code.
for(int j=0; j<5; j++) {
boolean flag1 = true;
for (int i=0; i<4; i++) {
if (card[i][j] == card[i][j+1]) {
}
else {
flag1 = false;
break;
}
}
if (flag1) {
System.out.println("BINGO! Congratulations, you have won!");
displayBoard(card, card2, card3, card4);
System.exit(0);
flag = false;
break;
}
}
if (flag) {
int i=0, j=0;
boolean flag2 = true;
while (i<5 && j<5) {
if (i!=2 && j!=2) {
if (card[i][j]==card[i+1][j+1]) {
` }
else flag2 = false;
break;
}
i++;
j++;
}
if (flag2) {
System.out.println("BINGO! Congratulations, you have won!");
displayBoard(card, card2, card3, card4);
System.exit(0);
flag = false;
}
else {
i=4;
j=0;
flag2 = true;
while (i<5 && j<5) {
if (i!=2 && j!=2) {
if (card[i][j]==card[i+1][j+1]) {
` }
else {
flag2 = false;
break;
}
}
i--;
j++;
}
if (flag2) {
System.out.println("BINGO! Congratulations, you have won!");
displayBoard(card, card2, card3, card4);
System.exit(0);
flag = false;
}
}
}
return(flag);
}

Java Multi-Dimensional Arrays in a Method

I'm knew with multi-dimensional arrays and I kind of know the basics but I'm stuck on combining them into a boolean method. In this case, I'm trying to find out how I can make this method simplified which will function as:
Comparing one array with a location (row:column) to another array (with the same location).
If all locations from both arrays match, it should return true.
The method below works with what I have for my code but I want to know the proper way on how to not "hard code" the numbers single handedly. Would I need to use a nested for loop for comparing both arrays?
Thanks for the assistance~
public static boolean gameIsWon(int[][] workingPuzzle, int[][] solvedPuzzle)
{
if (workingPuzzle[0][0] == solvedPuzzle[0][0] &&
workingPuzzle[0][1] == solvedPuzzle[0][1] &&
workingPuzzle[0][2] == solvedPuzzle[0][2] &&
workingPuzzle[0][3] == solvedPuzzle[0][3] &&
workingPuzzle[0][4] == solvedPuzzle[0][4] &&
workingPuzzle[0][5] == solvedPuzzle[0][5] &&
workingPuzzle[0][6] == solvedPuzzle[0][6] &&
workingPuzzle[0][7] == solvedPuzzle[0][7] &&
workingPuzzle[0][8] == solvedPuzzle[0][8] &&
workingPuzzle[1][0] == solvedPuzzle[1][0] &&
workingPuzzle[1][1] == solvedPuzzle[1][1] &&
workingPuzzle[1][2] == solvedPuzzle[1][2] &&
workingPuzzle[1][3] == solvedPuzzle[1][3] &&
workingPuzzle[1][4] == solvedPuzzle[1][4] &&
workingPuzzle[1][5] == solvedPuzzle[1][5] &&
workingPuzzle[1][6] == solvedPuzzle[1][6] &&
workingPuzzle[1][7] == solvedPuzzle[1][7] &&
workingPuzzle[1][8] == solvedPuzzle[1][8] &&
workingPuzzle[2][0] == solvedPuzzle[2][0] &&
workingPuzzle[2][1] == solvedPuzzle[2][1] &&
workingPuzzle[2][2] == solvedPuzzle[2][2] &&
workingPuzzle[2][3] == solvedPuzzle[2][3] &&
workingPuzzle[2][4] == solvedPuzzle[2][4] &&
workingPuzzle[2][5] == solvedPuzzle[2][5] &&
workingPuzzle[2][6] == solvedPuzzle[2][6] &&
workingPuzzle[2][7] == solvedPuzzle[2][7] &&
workingPuzzle[2][8] == solvedPuzzle[2][8] &&
workingPuzzle[3][0] == solvedPuzzle[3][0] &&
workingPuzzle[3][1] == solvedPuzzle[3][1] &&
workingPuzzle[3][2] == solvedPuzzle[3][2] &&
workingPuzzle[3][3] == solvedPuzzle[3][3] &&
workingPuzzle[3][4] == solvedPuzzle[3][4] &&
workingPuzzle[3][5] == solvedPuzzle[3][5] &&
workingPuzzle[3][6] == solvedPuzzle[3][6] &&
workingPuzzle[3][7] == solvedPuzzle[3][7] &&
workingPuzzle[3][8] == solvedPuzzle[3][8] &&
workingPuzzle[4][0] == solvedPuzzle[4][0] &&
workingPuzzle[4][1] == solvedPuzzle[4][1] &&
workingPuzzle[4][2] == solvedPuzzle[4][2] &&
workingPuzzle[4][3] == solvedPuzzle[4][3] &&
workingPuzzle[4][4] == solvedPuzzle[4][4] &&
workingPuzzle[4][5] == solvedPuzzle[4][5] &&
workingPuzzle[4][6] == solvedPuzzle[4][6] &&
workingPuzzle[4][7] == solvedPuzzle[4][7] &&
workingPuzzle[4][8] == solvedPuzzle[4][8] &&
workingPuzzle[5][0] == solvedPuzzle[5][0] &&
workingPuzzle[5][1] == solvedPuzzle[5][1] &&
workingPuzzle[5][2] == solvedPuzzle[5][2] &&
workingPuzzle[5][3] == solvedPuzzle[5][3] &&
workingPuzzle[5][4] == solvedPuzzle[5][4] &&
workingPuzzle[5][5] == solvedPuzzle[5][5] &&
workingPuzzle[5][6] == solvedPuzzle[5][6] &&
workingPuzzle[5][7] == solvedPuzzle[5][7] &&
workingPuzzle[5][8] == solvedPuzzle[5][8] &&
workingPuzzle[6][0] == solvedPuzzle[6][0] &&
workingPuzzle[6][1] == solvedPuzzle[6][1] &&
workingPuzzle[6][2] == solvedPuzzle[6][2] &&
workingPuzzle[6][3] == solvedPuzzle[6][3] &&
workingPuzzle[6][4] == solvedPuzzle[6][4] &&
workingPuzzle[6][5] == solvedPuzzle[6][5] &&
workingPuzzle[6][6] == solvedPuzzle[6][6] &&
workingPuzzle[6][7] == solvedPuzzle[6][7] &&
workingPuzzle[6][8] == solvedPuzzle[6][8] &&
workingPuzzle[7][0] == solvedPuzzle[7][0] &&
workingPuzzle[7][1] == solvedPuzzle[7][1] &&
workingPuzzle[7][2] == solvedPuzzle[7][2] &&
workingPuzzle[7][3] == solvedPuzzle[7][3] &&
workingPuzzle[7][4] == solvedPuzzle[7][4] &&
workingPuzzle[7][5] == solvedPuzzle[7][5] &&
workingPuzzle[7][6] == solvedPuzzle[7][6] &&
workingPuzzle[7][7] == solvedPuzzle[7][7] &&
workingPuzzle[7][8] == solvedPuzzle[7][8] &&
workingPuzzle[8][0] == solvedPuzzle[8][0] &&
workingPuzzle[8][1] == solvedPuzzle[8][1] &&
workingPuzzle[8][2] == solvedPuzzle[8][2] &&
workingPuzzle[8][3] == solvedPuzzle[8][3] &&
workingPuzzle[8][4] == solvedPuzzle[8][4] &&
workingPuzzle[8][5] == solvedPuzzle[8][5] &&
workingPuzzle[8][6] == solvedPuzzle[8][6] &&
workingPuzzle[8][7] == solvedPuzzle[8][7] &&
workingPuzzle[8][8] == solvedPuzzle[8][8]
)
return true;
else
return false;
}

You need to learn about loops.
And about storing a two-dimensional matrix in a one-dimensional array using index mapping (which is easier to handle than a two-dimensional array).
But in this particular case:
return java.util.Arrays.deepEquals(workingPuzzle, solvedPuzzle);

Use nested for loops based on the array lengths.
public static boolean gameIsWon(int[][] workingPuzzle, int[][] solvedPuzzle) {
if(workingPuzzle.length != solvedPuzzle.length) {
return false;
}
for(int i = 0; i < workingPuzzle.length; i++) {
if(workingPuzzle[i].length != solvedPuzzle[i].length) {
return false;
}
for(int j = 0; j < workingPuzzle[i].length; j++) {
if(workingPuzzle[i][j] != solvedPuzzle[i][j]) {
return false;
}
}
}
return true;
}

Java: Wildcard Pattern Matching

I have been trying to solve the Wildcard pattern matching and I have found a working solution in the below link:
http://www.geeksforgeeks.org/wildcard-character-matching/
I have written an Equivalent java code for the C code given in the above link, which is:
public class wildcard
{
public static void main(String[] args)
{
test("g*ks", "geeks");
//test("g*k", "gee");
//test("c*d*", "cad");
}
static boolean matches(String format, String data)
{
if (format.length() == 0 && data.length() == 0)
{
return true;
}
if ((format.charAt(0) == '*' && format.charAt(1) != 0 && data.length() == 0) && (format.length() != 0 && data.length() != 0))
{
return false;
}
if ((format.charAt(0) == '?' || format.charAt(0) == data.charAt(0)) && (format.length() != 0 && data.length() != 0))
{
return matches(format.substring(1), data.substring(1));
}
if ((format.charAt(0) == '*')&& (format.length() != 0 && data.length() != 0))
{
return matches(format.substring(1), data) || matches(format, data.substring(1));
}
return false;
}
static void test(String first, String second)
{
System.out.println(matches(first, second));
}
}
On Execution, a String out of bounds Exception is thrown, which is:
Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: 1
at java.lang.String.charAt(String.java:658)
at wildcard.matches(wildcard.java:29)
at wildcard.matches(wildcard.java:36)
at wildcard.matches(wildcard.java:42)
at wildcard.matches(wildcard.java:42)
at wildcard.matches(wildcard.java:36)
at wildcard.test(wildcard.java:52)
at wildcard.main(wildcard.java:16)
I can see that this exception occurs at the CharAt() method, is there any other way to make this work??

:)
First I noticed that the code && (format.length() != 0 && data.length() != 0) is not on the original code from the page you provide and are causing conflicts with your algorithm so I remove it and it looks like this:
static boolean matches(String format, String data) {
if (format.length() == 0 && data.length() == 0) {
return true;
}
if (format.charAt(0) == '*' && format.charAt(1) != 0 && data.length() == 0) {
return false;
}
if (format.charAt(0) == '?' || format.charAt(0) == data.charAt(0)) {
return matches(format.substring(1), data.substring(1));
}
if (format.charAt(0) == '*') {
return matches(format.substring(1), data) || matches(format, data.substring(1));
}
return false;
}
The problems I talked about are in the second condition you have data.length() == 0 and in the code I remove was data.length() != 0, so that condition was always false because the length cannot be 0 and not 0 at the same time.
I discovered two problems. The first one was that some cases like matches("ge?ks*", "geeksforgeeks") end up with having a single wildcard at the format and crashed on if (format.charAt(0) == '*' && format.charAt(1) != 0 && data.length() == 0) because of format.charAt(1). To solve this I add the next code to the algorithm:
if (format.length() == 1 && format.charAt(0) == '*')
return true;
The other problem was when the format was empty but still have data and solve it with:
if (format.length() == 0 && data.length() > 0)
return false;
The final algorithm looks like this:
static boolean matches(String format, String data) {
if (format.length() == 0 && data.length() == 0)
return true;
if (format.length() == 1 && format.charAt(0) == '*')
return true;
if (format.length() == 0 && data.length() > 0)
return false;
if (format.charAt(0) == '*' && format.charAt(1) != 0 && data.length() == 0)
return false;
if (format.charAt(0) == '?' || format.charAt(0) == data.charAt(0))
return matches(format.substring(1), data.substring(1));
if (format.charAt(0) == '*')
return matches(format.substring(1), data) || matches(format, data.substring(1));
return false;
}

Running my java code works in debugger but not in run

Running my java code works in debugger but not in run. In the eclipse debugger it shows my jframes.
However when I run it, my frame doesn't appear whatsoever.
I believe I messed up my EventListener and all that.
private class ButtonHandler implements ActionListener{
JButton button;
public void actionPerformed(ActionEvent event) {
find(event.getSource());
button = buttonHolder[indexK[kCount-1]][indexJ[jCount-1]];
if((button.getIcon() == red && choice1 == 1) || (button.getIcon() == green && choice1 == 0)){
JOptionPane.showMessageDialog(null, "You chose the wrong color!");
return;
}
if(turn ==1){
if(clicks != 1){
if(button.getIcon() == red){
clicks++;
temp = button;
}else if (button.getIcon() == green){
clicks++;
temp = button;
}else{
kCount=0;
jCount=0;
}
}else{
if((button.getIcon() == green) || (button.getIcon() == red)){
//do nothing
}else if(temp.getIcon() == green && (grid[indexK[1]][indexJ[1]] == 2 || grid[indexK[1]][indexJ[1]] == 3 || grid[indexK[1]][indexJ[1]] == 4) && button.getIcon() != green && ((indexK[0]+1 ==indexK[1] && indexJ[0] == indexJ[1]) || (indexK[0] ==indexK[1] && indexJ[0]+1 == indexJ[1]) || (indexK[0] ==indexK[1] && indexJ[0]-1 == indexJ[1])) ){
temp.setIcon(null);
button.setIcon(green);
grid[indexK[1]][indexJ[1]] = 2;
if(indexK[0] == 0 || indexK[0]== 9){
grid[indexK[0]][indexJ[0]] = 4;
}else{
grid[indexK[0]][indexJ[0]] =3;
}
found = 2;
}else if(temp.getIcon() == red && (grid[indexK[1]][indexJ[1]] == 1 || grid[indexK[1]][indexJ[1]] == 3 || grid[indexK[1]][indexJ[1]] == 5) && button.getIcon() != red && ((indexK[0]+1 ==indexK[1] && indexJ[0] == indexJ[1]) || (indexK[0] ==indexK[1] && indexJ[0]+1 == indexJ[1]) || (indexK[0]-1 ==indexK[1] && indexJ[0] == indexJ[1]))){
temp.setIcon(null);
button.setIcon(red);
grid[indexK[1]][indexJ[1]] = 1;
if(indexJ[0] == 0 || indexJ[0]== 9){
grid[indexK[0]][indexJ[0]] = 5;
}else{
grid[indexK[0]][indexJ[0]] =3;
}
found = 2;
}
clicks=0;
kCount=0;
jCount=0;
}
}
}
}
}
if you don't see any problems, can you think of a reason why it might be messing up?

First, double check that you're running it in the same mode. A program made for Applet mode is not the same as Application.
If that doesn't work:
If running as an Applet:
Check that you have an init function.
If running as an Application:
Check that you define a main class in your run configuration. If you did, make sure you are running a main() method within it.