Alex Ba

Seems as though doing things on paper first makes programming easier.
Wish my professor would've mentioned that

Hey I figured it out.
while(first < voters) { voteString = kb.nextLine(); track = 0; while(track < voteString.length()) { char c = voteString.charAt(track); ballot[first][second] = Integer.parseInt(Character.toString(c)); track = track + 2; second++; } second = 0; first++; } } is the current while loop. It seems to be working.

Patricia Samuel wrote:Hi Alex,

Please let me know what input this line takes for the test case you have provided -

# System.out.println("\nPlease enter your vote");
# System.out.println("Please enter votes: 1,2,3,4,5 etc");
# Scanner kb = new Scanner(System.in);

Thanks
Patricia

That input is in the while loop
voteString = kb.nextLine();

The input would be something like 1,2 or 2,1 aka, which person is your number 1 preference, and which is your number 2. From there, that string is getting split up into individual characters and entered into various slots in the array. It's not doing that.

I should add the main class:

public static void main(String[] args) { // TODO code application logic here election election1 = new election(); System.out.println("Please enter the number of candidates"); Scanner kb = new Scanner(System.in); int i = kb.nextInt(); election1.setNames(i); System.out.println("Please enter the number of voters"); election1.voters = kb.nextInt(); election1.printNames(); election1.vote(); election1.printVotes(); }

public int candidates; public String[] names; public int[][] ballot; public int voters; public void setNames(int i) { candidates = i; names = new String[candidates]; Scanner kb = new Scanner(System.in); int n = 0; String name; while(n < candidates) { System.out.println("Enter a candidate"); name = kb.nextLine(); names[n] = name; n++; } } public void printNames() { int n = 0; System.out.println("The candidates are:"); while (n < candidates) { System.out.print(names[n] + " "); n++; } } public void vote() { System.out.println("\nPlease enter your vote"); System.out.println("Please enter votes: 1,2,3,4,5 etc"); Scanner kb = new Scanner(System.in); // int k = voters * candidates; ballot = new int[voters][candidates]; int first = 0, second = 0; String voteString; //int n = voters * candidates; while(first < voters) { while(second < candidates) { voteString = kb.nextLine(); int count = voteString.length() - 1; int track = 0; while(track < count - 2) { char c = voteString.charAt(track); int k = Integer.parseInt(Character.toString(c)); ballot[first][second] = k; track = track + 2; } second++; } second = 0; first++; } } public void printVotes() { int first = 0, second = 0; while(first < voters) { while(second < candidates) { System.out.println(ballot[first][second]); second++; } second = 0; first++; } }

If you enter 2 candidates and 3 voters, instead of entering votes 3 times, you enter them 6 and I can't see why. Also, for the printVotes method, it just prints 0s. Anyone see any huge holes in my logic? I can't figure out for the life of me why it's not working.

??

But it prints "Please Vote" and then doesn't give an opportunity to fill q...

while(s < n) { System.out.println("Please vote"); String q = kb.nextLine(); char c = q.charAt(place); k = Integer.parseInt(Character.toString(c)); votes[f][s] = k; place = place + 2; s++; }

I'm getting a Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: 0

at
char c = q.charAt(place);

And I'm not entirely sure why. Place is initialized and set to 0.

while((!newStack.isEmpty()) && (j != 0)) { System.out.println("Enter in an operand, operator, or 0 to stop"); x = kb.next(); j = Integer.parseInt(x); newStack.push(x); }


In the event that you enter a 0, it parses it, then pushes it onto the stack, and then ends the loop. I can't figure out why it's pushing it onto the stack if one of the loop parameters is met? (j != 0)

To clarify, I'm used to using classes and methods and whatnot. I'm not used to traversing 2 different lists from from a class (as opposed to a main.)

Like, in a main:

Linkedlist list1 = new Linkedlist; Linkedlist list2 = new Linkedlist;


Or in my insert method, you're working with one list and not two. I'm confused about how to traverse two DIFFERENT lists outside the main.

But how would I do that in a method from a class? In my head it works out like so:

First, check both lists' lengths, and if they are unequal equals returns false
Then, run a while loop that traverses list a, and a nested while loop that traverses list b. AKA,

List a = {1,2,3}
List b = (3,1,2}

1 against 3 = false, increment b, 1 against 1 true;
2 against 3 = false, increment b, 2 against 1 false, increment b, 2 against 2 = true;
3 against 3 = true;

Make sense?

The problem I'm having is I can't seem to get my mind around using 2 lists. I'm so used to things like:
current = head (setting the node to be checked as the first item in a list)

But wouldn't I then need like, currenta and currentb? And how would I write that? currenta = .... (since I have 2 lists)

For my current project, I have to write a method that checks to see if one linked list is equal to another. They must be the same length, but the nodes don't have to be in the same spot. AKA

1
3
8

is equal to

1
8
3



But the problem is I can't think up a way to check the values of 2 different lists from the class and not the main? Looking for logic help, not code.

But I don't understand, you're setting current to head, and that means current doesn't have a previous value, so previous would be null, no?

public void delete(int i) { IntNode current = head; IntNode previous = null; boolean done = false; while((current != null) && (!done)) { if(current.value == i) { if(current.previous == null) { head = current.next; } else if(current.next == null) { previous.next = null; } else { previous.next = current.next; } done = true; } else { current = current.next; } } }

When there's only one item in the list and it's supposed to be deleted, it's not. And when there's 2 items in the list that are both supposed to be deleted, the first isn't and the second throws a nullpointerexception for the previous.next = null line. I don't understand why though.

I can't find the problem with my print statement.

public void print() { IntNode current = tail; while(current.previous != null) { System.out.println(current.value); current = current.previous } }


The insert method:

public void insert(int i) { IntNode newnode = new IntNode(i, null, null) <-----------could it have something to do with I'm setting the next and previous to null here? I don't understand this line IntNode current; if(!belongs(i)) { if(head == null) { head = newnode; tail = newnode; } else{ newnode.next = head; newnode.previous = null; head = newnode; current = newnode.next; current.previous = newnode; } } }



Some of the syntax might be wrong, my compiler doesn't allow copying. Is there a mistake I'm not seeing?