Say You have the following values in a stack
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My requirement is to put in all unique strings and remove duplicates from the stack.The comparison has to be done only in Stacks.Use of any other Arrays ,Hash tables to store values or comparing is Prohibited.what is the minimum number of stacks required.
Write a method compressDuplicates that accepts a stack of integers as a parameter and that replaces each sequence of duplicates with a pair of values: a count of the number of duplicates, followed by the actual duplicated number. For example, suppose a variable called s stores the following sequence of values:
bottom [2, 2, 2, 2, 2, -5, -5, 3, 3, 3, 3, 4, 4, 1, 0, 17, 17] top
If we make the call of compressDuplicates(s);, after the call s should store the following values:
bottom [5, 2, 2, -5, 4, 3, 2, 4, 1, 1, 1, 0, 2, 17] top
This new stack indicates that the original had 5 occurrences of 2 at the bottom of the stack followed by 2 occurrences of -5 followed by 4 occurrences of 3, and so on. This process works best when there are many duplicates in a row. For example, if the stack instead had stored:
bottom [10, 20, 10, 20, 20, 10] top
Then the resulting stack after the call ends up being longer than the original:
bottom [1, 10, 1, 20, 1, 10, 2, 20, 1, 10] top
If the stack is empty, your method should not change it. You may use one queue as auxiliary storage to solve this problem. You may not use any other auxiliary data structures to solve this problem, although you can have as many simple variables as you like. You may not use recursion to solve this problem. For full credit your code must run in O(n) time where n is the number of elements of the original stack.
I wrote a code but still having a problem with it , am I allowed to use 3 while loops ?
public void compressDuplicates(Stack<Integer> s ){
Stack<Integer> backup= new Stack<Integer>();
int count = 1;
while(!s.isEmpty()){
int temp = s.pop();
[Code] .....
// example 1
Expected output : bottom [5, 2, 2, -5, 4, 3, 2, 4, 1, 1, 1, 0, 2, 17] top
My output: //bottom [17, 2, 2, 2, 2, 2, -5, -5, 3, 3, 3, 3, 4, 4, 1, 0, 17, 17] top
This method keeps throwing a NullPointerException. Not only that, but its not doing what I want it to do.
Heres the code:
/*
Remove all the numbers from the queue and push onto the stack until an operator is reached
*/
private static void processQueue() {
// Check what is at the front of the queue. If an operator is found or the queue is empty, exit method.
while(queue.front() != null || !queue.front().equals("*") || !queue.front().equals("/") || !queue.front().equals("%")
|| !queue.front().equals("+") || !queue.front().equals("-"))
{
stack.push(queue.removeFront()); // push the operand onto the stack
}
}
Here is the method that calls the processQueue() method
/*
Process the mathematical expression using a stack and a queue
*/
private static double processExpression() {
// insert all elements from the stack to the queue for processing
while(stack.top() != null) {
queue.insertBack(stack.pop());
[Code] .....
I am having an array of strings and i want to find out whether these strings contained in the array contain a similar character or not.For example i am having following strings in the array of string:
aadafbd
dsfgdfbvc
sdfgyub
fhjgbjhjd
my program should provide following result: 3 because i have 3 characters which are similar in all the strings of the array(f,b,d).
I am looking for a program to generate a unique alphanumerical identifier that is not too long; for example would start out with 6 digits like a licence plate or a postal code ex: AAA001 and use up all the possible combinations until 999ZZZ (just an example) and then when the possibilities are exhausted a 7th digit is added and so on. It matters not if they are sequential, the identifier just needs to be unique and not be too hard to remember (also i don't want to use ip adress or any personal identification). How I can accomplish this using java.
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View Replies View RelatedI want a completely unique GUI with unique buttons, like I could make it a giraffe if I wanted to! (not going to, but a giraffe seemed like a pretty irregular shape) ....
View Replies View RelatedI am attempting to count the unique strings (a.k.a flowers) in the array along with a count of any duplicates. An example is embedded in my code below. I've only pasted the part of the program I am having trouble with. I can't figure out what I am doing incorrectly.
private void displayFlowers(String flowerPack[]) {
// TODO: Display only the unique flowers along with a count of any duplicates
/*
* For example it should say
[Code]....
I'm planning to make a unique news app for android (maybe iOS later) and I am fairly experienced in Java. Im thinking to most likely use RSS feeds, but am unaware how to implement them into JAVA.
View Replies View RelatedSay I have a class called ClassA which I want to hold my data. Now inside ClassA want to hold instances of a class lets call ClassB. So far we are here.
import blah.B
public class A {
private B myB;
(Getters setters etc)
public String getBString() {
B.getString();
}
}
However I want to have multiple extensions of ClassB which have UNIQUE static variables.
public class B-1 extends B {
private static String mString;
private static int mInt;
}
The problem I have run into is I can't have subclasses with their own static variables. I need the A class to hold any type of B class. How can I manage this?meant
public String getBString{
return B.getString();
}
I can sort strings in a collection by uppercase and then lowercase though I was wondering if there is any way of doing it in reverse, sorting by lowercase then by uppercase.
View Replies View RelatedI'm trying to count the number of elements in an ArrayList which also have duplicates. So for example, in an ArrayList of strings which contains cat, cat, dog, horse, zebra, zebra, the answer should be two.
If an element is found to be a duplicate, that element should then be exempt from the search so if that element is found again it should not increase the duplicate count.
Here is my code:
public int countDuplicates() {
int duplicates = 0;
// TODO: Write the code to get the number of duplicates in the list
for (int i = 0; i < list.size()-1;i++) {
boolean found = false;
[Code] ....
I know it's wrong because right now it's still increasing the duplicate count for elements that have already been detected as duplicates. How can I make it stop doing this?
THE PROGRAM DOES NOT HAVE ERRORS. FILL THE 2D ARRAY WITHOUT DUPLICATES VALUES. AND DISPLAY IF THE ARRAY IS MAGIC SQUARE OR NOT.
View Replies View RelatedI'm struggling with that piece of code, my intention is to check for the object I want to add before adding it, so there won't be any duplicate on my list. I'm not sure how could I do that, since I'm working with objects.
Person is a class with few parameters such as id, name, and few others.
I guess I should search for a person with the same id, since that has be unique, but can't get it right.
private ArrayList<person> model= new ArrayList<>();
//...
if (model.contains(person))throw new IllegalArgumentException("duplicate");
else model.addElement(person);
It's supposed to count all of the duplicates in an array and print out how many occurrences of the value starting at whatever index, or if there are no duplicates state that. Basically:
No duplicates with value 1 beyond Index 0
There are 3 more occurrences of value 2 starting at index 1
There are 2 more occurrences of value 2 starting at index 2....
This is what I've got so far:
Java Code:
public static void main(String[] args) {
int[] arr = {1, 2, 2, 3, 4, 2, 4, 3, 0, 5, 3, 2};
for(int i = 0; i<arr.length; i++){
int count = 0;
for(int j = i+1; j<arr.length; j++){
if((arr[j] == arr[i]) && (i!=j)){
count++;
System.out.print("There are " + count + " more occurrences of ");
System.out.println(arr[i] + " starting at index " + i);
}
}
}
} mh_sh_highlight_all('java');
I found out what my next java class project is, and i am trying to get a head start on it. It is a simple address book. it needs to have 4 choices that get cycled through until quit is chosen:
1. add business contact
2. add personal contact
3. display contacts
4. quit
I have made an abstract contact class with a personal subclass and business subclass(all 3 are required). they have all been made, with set/get methods(the wonders of encapsulation and polymorphism have finally hit home!). The main program needs to add a new subclass object when chosen, and it needs to accept and store contacts by type
So, i am figuring 2 object arraylists for business/personal.
My question is: how do you create an object without having a name for it already programmed? Does it even need to have a unique name, since it would be stored in a seperate index and/or arraylist?
Contact contact = new Contact();
this.firstname = "Be";
this.secondname ="Ginner";
this.phonenumber = "921-456-0102";
personalArray.add (contact);
Then cycle through, changing the properties, and add again to personalArray?
I have a class called Sprite which extends its several subclasses. Therefore, there are a lot of different Sprite classes, the thing is however, most of those subclasses have unique types of variables which I want to only be included in those particular subclasses, not anywhere else. For instance, I might have a variable measuring distance in one subclass, and in another subclass there might be a height variable inherent. I don't want the first subclass to have both variables, neither the second or the main class. Because before I initialize my subclasses, I need to create the constructors of those subclasses in the main Sprite class first because it doesn't have the unique variables which those classes consist of. How do I prevent that? Now I have to create the unique constructors and variables for every subclass, when I only want them in their associated classes.
View Replies View RelatedWhich string method to search a particular character in a string whether a particular character is there or not . Suppose my String is like............
String s = "Java.";
How I can find the character " . " in above string "Java." is present or not . What is the string method to search that "."
We have a customer requirement , need to generate a unique number(configurable) and it should not skip at any situation.
We have about 3- 4 modules where we need to generate. And update in some xyz table column each time. We are doing this as below approach.
We generate that number in separate transaction and that too in end of the business logic and then move to success page. But recently it got skipped due to time out error during updating .... the db usage is huge at some time and multi user doing operation which intern generate multiple number of this time.
But as DB is not responded and complete transaction is roll out and this number got skipped...
I am stuck on this exercise and I don't know what exactly is wrong. I think it's something with the .remove and the for each loop, but I am not sure.
public class seven {
public static void main(String[] args) {
ArrayList<String> list = new ArrayList<String>();
list.add("aaa");
list.add("brr");
list.add("unni");
[Code] ....
This is what i get
Exception in thread "main" java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(Unknown Source)
at java.util.ArrayList$Itr.next(Unknown Source)
at seven.removeDuplicates(seven.java:24)
at seven.main(seven.java:18)
I have taken array int[] a = {33,33,5,5,9,8,9,9};
In this array so many values are duplicates means 33 comes twice & 5 also comes twice & 9 comes three times. But I want to count the first value which is duplicate means 33 is first value which comes twice so answer would be 2.
I try:
public class FindFirstDuplicate {
public static void main(String[] args) {
int c=0;
int[] a = {33,33,5,5,9,8,9,9};
outerloop:
for(int i = 0; i < a.length; i++) {
[code]....
Output:
33
Count: 1
This code is not best way to find the duplicate elements in a given array. Any alternative method for an optimized code.
Java Code:
import java.util.Arrays;
public class Find_Dupliicate_ArrayElement {
public static void main(String[] args) {
int[] Array1 = {1, 9,8,1,2,8,9,7,10, -1, 1, 2, 3, 10, 8, -1};
// Store the array length
int size = Array1.length;
//Sort the array
Arrays.sort(Array1);
[code]....
I have a HashSet, which I created to prevent duplicates upon output, but of course it's printing duplicates(or else I wouldn't be posting this). The order of my output does not matter, nor the input. The data type is String in the format (x + "," + z), where x and z are integers, creating a collection of coordinate sets. So to prevent the output of duplicates, I'm trying to get rid of the duplicates before they are added to the collection.
I've tried doing a '.equals()' string comparison but what happens is, since my string is added via one variable, it compares itself to itself and if itself equals itself it won't be added to the collection. I really need to keep this as a comparison of a single variable, because creating a key for each value would be sooo ridiculous for this volume of inputs.
So, with that being said, I would like to add one copy of the string, discard the duplicates, and do this thousands of times..
At our banking application , there is a requirements to send unique reference number for some payment transaction.How can I do this at Prod while we have three app servers and we don't have DB at our end (front end site)?
View Replies View RelatedI'm trying to remove duplicates from table. I want to remove only those rows which are both id and data equal. My code failed at fourth line.
int i=jTable1.getSelectedRow();
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
jXDatePicker1.setFormats(dateFormat);
String date = dateFormat.format(jXDatePicker1.getDate()).toString();
String c1=jTable1.getValueAt(i, 0).toString();
String c2=jTable1.getValueAt(i, 1).toString();
[Code] .....
How to sort data from a .csv file. The file has a column that contains duplicate groups, and a column that has duplicate employee id's. I need to take the data and sort it into rows. The employee's id will be in the first column, then the groups the employees belong in will occupy the following columns. The groups and employees are dynamic.
groups| empId
-----------------
Group A| a1234 |
Group A| e3456 |
Group A| w3452 |
Group A| d3456 |
Group A| j7689 |
[Code] ....
I want to format the .csv as follows:
--------------------------
empId | group 1 | group 2 |
--------------------------
a1234 | group A | group B |
---------------------------
w3452 | group A | group B |
---------------------------