Removing A Key From Hasmap Within Hashmap
Dec 1, 2014
SO my current code creates a graph with vertices and weighted edges. This data is stored in a hashmap. The key of the hashmap is the vertex and the value is a second hashmap. This second hashmap contains the edges with the vertex it connected to as the key and the weight as the value. My current problem is that when i try to remove vertices they are removed from the key set but they stay in the value(the second hashmap) as the key for that hashmap. IS THERE A WAY TO REMOVE THE VERTEX FROM THE KEYSET OF THE SECOND HASHMAP.
Code is as follows
constructor{
adjacencyMap = new HashMap<V, HashMap<V, Integer>>();
dataMap = new HashSet<V>();
}
removal method{
if(dataMap.contains(vertex)){
[Code]...
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Mar 25, 2015
For some reason the following code is not removing whitespace from my string:
temp = sb.toString().trim().replace("s+", " ");
I have printed the string before and after the implementation of the methods above and there is not change in the whitespace of the string.
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Sep 26, 2014
I am trying to remove a character from string as below
public String reomveChar(String str, int n) {
if(0<=n & n<=(str.length()-1)){
//str.charAt(n)
char o=str.charAt(n);
return str.replace("o","");
//a.replace("o","");
}
return null;
}'
what is the best way to remove it.
If i call like
removeChar("hello", 1) i should see hllo.
When there are more than one way to do a challenge in java which one to choose as best way.
What is the criteria to decide one particular way of writing code is best among say 'n' different number of ways.
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Jan 28, 2015
How do I write a program that has words in an array and output that array without the vowels?
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Aug 24, 2014
Referring Code 1, the book says line 16 of the code removes the element "Three" but line 17 does not remove the element "Four" because of Statement 1. The question is does remove(Object o) method invoke the == or the equals method because statement 1 and 2 seem to be in conflict
Statement 1:
Two objects are equal if their object references point to the same object. (which is nothing but definition of ==)
Statement 2:
The author refers to Statement 1 and says "As mentioned earlier, the method remove compares the objects for equality before removing it from ArrayList by calling method equals."
Java Code:
import java.util.ArrayList;
public class DeleteElementsFromArrayList {
public static void main(String args[]) {
ArrayList<StringBuilder> myArrList = new ArrayList<>();
StringBuilder sb1 = new StringBuilder("One");
[Code] ....
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Sep 18, 2014
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)
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Mar 20, 2014
public class werek4d {
public static void main(String[] args) {
int counter = 1;
int[] anArray = new int[101] ;
for (int i = 0; i <= 99; i++){
anArray[i] = i + 1;
System.out.println(i + ": " + anArray[i] + " ");
[Code] ....
My aim is to generate a lists containing 1 to 100. I will then count the number of integers divisible by 3. After doing so, I want to delete the integers that are NOT divisible by 3 in the lists. I tried doing it, but I seem to keep on getting the same lists.
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Feb 28, 2007
I have a string from which I need to remove all of the newlines, tabs, and spaces. Here is the code I wrote:
inputString = inputString.replaceAll(" ", "");
inputString = inputString.replaceAll("
", "");
inputString = inputString.replaceAll(" ", "");
It removes the spaces just fine but not the newlines or tabs. How can I do this?
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May 7, 2014
I just need to write a simple program/function that replaces certain letters from a string (i.e. censor( "college", "aeiou" ) returns "cllg"). I'm trying to get the code right first, and then write a function for it.I basically just thought that I would iterate over the first string, and once I had the first character, I would then iterate over the second string, to see if the character exists. I'm getting a "dead code" error on my second loop because I put the second "break."
public class ap {
public static void main(String [] args){
String s = "Hello";
String s2 = "aeiou";
[code]....
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Oct 3, 2014
I am working on a java program that is called OrderedVector which is basically a storage or list that grows and shrinks depending on the amount of data is put in. Most of the methods in my code are correct and working, the only real issue I have lies with either the remove(E obj) method or remove(int index) method. This is the driver I am currently using to test my remove method,
public class Tester {
public static void main(String[] args) {
OrderedListADT<Integer> v;
v = new OrderedVector<Integer>();
for(int i = 0 ; i <= 9; i++){
v.insert(i);
[code]....
the output I am receiving is
Removing 0
Size of data structure is 9
Removing 1
Size of data structure is 8
Removing 2
Size of data structure is 7
[code]....
As you can see, when I am calling the second for loop, none of the elements are being removed by my methods but the first for loop is working just fine.
Here is my code for the OrderedVector
package data_structures;
import java.util.Iterator;
import java.util.NoSuchElementException;
public class OrderedVector<E> implements OrderedListADT<E>{
private int currentSize, maxSize;
private E[] storage;
public OrderedVector(){
currentSize = 0;
[code]....
So overall, my remove method should implement binary search and remove elements using either an index or the object value type.
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Dec 18, 2014
I was trying remove duplicates element from my array without using collection API but i didn't got any output from my code.Although it is compiled successfully but on execution it didn't give any output. I guess there must be some problem in function Duplicate
Java Code:
class Union {
public static void main(String...s) {
Union M=new Union();
int x[]=new int[]{1,0,1,4,10,10,10,3,567,4,3,33};
int y[]=new int[]{5,4,5,4,5,4,2,3,3,1,0};
int []w=M.merge(x,y);
[Code] .....
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Mar 23, 2015
I want to remove all numeric number in String text
String text = She was born in 1964,and now her age is 55;
String delim = ",";
StringTokenizer stringTok = new StringTokenizer(text, delim);
String f1 = "%-40s";
String h1 = String.format(f1, "Token list");
[Code] .....
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Apr 6, 2014
I'm not sure why but my infix string isn't removing the spaces. Here is the part of the code:
Scanner s = new Scanner(System.in);
System.out.println("Enter Infix express: ");
String infix = s.nextLine();
infix.replaceAll("\s", "").trim();
System.out.println(infix);
InfixtoPostfix convert = new InfixtoPostfix(infix);
String postfix = convert.toPostFix();
System.out.println("Converted Express: " + postfix);
Is there something I'm doing wrong? Here is the output when I run it:
Enter Infix expression:
(7 + x) * (8 – 2) / 4 + (x + 2)
(7 + x) * (8 – 2) / 4 + (x + 2)
Converted Expression: 7 x+ 8 – 2* /4 x 2++
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Jul 20, 2014
Ask the user to enter a sequence of at most 20 nonnegative integers. Your program should have a loop that reads the integers into an array and stops when a negative is entered (the negative number should not be stored). Invoke the average method to find the average of the integers in the array (send the array as the parameter).
how can I remove the negative number from the array and calculate the average of the posive elements without the negative ones? This is my code so far...
import java.util.Scanner;
import javax.swing.JApplet;
public class Parameters
{
//-------------------------------------
//Calls the average and minimum methods
//with different numbers of parameters
[code]....
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Nov 23, 2014
I am using a TreeSet to tokenize a string. The output is sorted with numeric first followed by words
E.g. 13 26 45 and before etc.....................
Is there a tidy way to remove the numeric?
Last bit of my code is :-
// print the words separating them with a space
for(String word : words) {
System.out.print(word + " ");
}
} catch (FileNotFoundException fnfe) {
System.err.println("Cannot read the input file - pass a valid file name");
}
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Apr 10, 2009
When you "system.out.print(arraylist)" an arraylist, it will give you something like [item1, item2].
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Apr 11, 2014
Im not sure why the nodes are not being deleted. Is a part of my logic wrong?
public void delete(String s) {
Node temp = find(s);
if (temp==null) {
return;
}
Node prevTemp = temp.prev;
Node nextTemp = temp.next;
[Code] .....
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Jun 11, 2014
I have a requirement where I need to read a file with so many carriage return line feeds. Attached is the file I am reading.
I have written a sample application to read the file and and remove these new line feeds but when I execute it, I see the line feed.
import java.io.*;
public class Main {
public static void main(String[] args) throws IOException{
[Code].....
Is there away to achieve this in attached output file?
This is just one record, but I have several records like these.
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May 6, 2014
I need to call the method to remove duplicates form my array, but it won't let me call the method, or I'm doing it incorrectly which is probably it.
import java.util.*;
public class C_6_15_EliminateDuplicates {
public static void main(String[] args) {
int[] numbers = new int[10];
Scanner input = new Scanner(System.in);
System.out.println("Enter " + numbers.length + " numbers: ");
for (int i = 0; i < numbers.length; i++)
[Code] ......
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Mar 8, 2014
So basically, if a line in a text file contains a certain string, that specific line will be deleted. It should probably be similair to this method?
Java Code:
/**
* Replace text.
* @param replace
* The text to replace.
* @param replaceWith
* The text to replace with.
*/
public static void replaceSelected(String replace, String replaceWith) {
try {
BufferedReader file = new BufferedReader(new FileReader("data/replacer.txt"));
[code]....
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Oct 20, 2014
I am writing a short quiz program, and when the user inputs their answer they hit the enter key (the are int). But the last question on my quiz is asking the user to they want to repeat the quiz, but when I run the program, it won't allow me to input any information. I can briefly remember my lecturer saying something about entering in a code after each int the user inputs but I can't remember what it was.
Here is a snippet of my code:
//Question 3
do{
System.out.println("Question 3- What Hollywood actor did Mila Kunis have a baby with recently?");
System.out.println( question3 + ".Ashton Kutcher 2.Bradly Cooper 3.Leonardo Dicaperio h.Get a hint");
answer3 = stdIn.nextInt();
if(answer3 != question3)
[Code] ....
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Apr 6, 2013
I have xml document, which is shown below:
After removing some nodes from the document ,i am getting empty lines in place of removed nodes,how to resolve this and get the proper xml document without any errors...
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE Message SYSTEM "TRD01.dtd">
<Message>
<Header>
<CounterPartyType>CLIENT</CounterPartyType>
<CreationTime>20134455</CreationTime>
[Code] ....
The xml output i am getting is
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<Message>
<Header>
<CounterPartyType>CLIENT</CounterPartyType>
<CreationTime>20134455</CreationTime>
[Code] ....
How to avoid empty lines in the xml doucment output. This is the method i am using to get the result
public void ValidateRecord(String xml){
try{
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder db = factory.newDocumentBuilder();
//parse file into DOM
/*DOMParser parser = new DOMParser();
parser.setErrorStream(System.err);
[Code] .....
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Jun 8, 2014
Question 1: I am working on an assignment where I have to remove an item from a String array (see code below). When I try to remove an item after entering it I get the following error "java.lang.NullPointerException." I am not sure how to correct this error.
Question 2: In addition, I am having trouble figuring out how to count the number of occurrences of each string in the array and print the counts. I've been looking at other posts but they are more advanced and I have not yet learned how to use some of the tools they are referring to.
private void removeFlower(String flowerPack[]) {
// TODO: Remove a flower that is specified by the user
Scanner input=new Scanner(System.in);
System.out.println();
System.out.println("Please enter the name of the flower you would like to remove:
[Code] ....
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Sep 26, 2014
In my code I read in a file of states and statecapitals then store them into a hashmap. I then ask the user what the capital is for the random state displayed.The problem I am having is getting the value for the random generated state. When I enter the correct capital for the state, it is still being marked incorrect. Here is my code.
Java Code: try {
Scanner scanner = new Scanner(file);
String[] values;
[code]....
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Jul 30, 2014
I have two Hasmaps as
Map<String,String> componentValueMap = new HashMap<String,String>();
Map<String,Map<String,String>> componentNameValueMap = new HashMap<String,Map<String,String>>();
I have for loop which are getting values from XML
XML structure as
<Raj>
<user>raj</user>
<password>123</password>
</Raj>
<Dazy>
<user>dazy</user>
<password>123</password>
</Dazy>
Now during first loop it will put user and password in map and after that put map refernce in another map. Same procedure for another values. But during iterating componentNameValueMap , i am getting Raj, Dazy as Key but not getting different values for them. I am getting latest values of Dazy in both Keys.
Because put method of Map<String,String> componentValueMap is replacing values. But I don't to replace them and want to get different values for different keys.
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Oct 23, 2014
I am trying to retrieve a object from a hashMap not I am not sure what is wrong. I am trying to calculate if a car was speeding. They're 5 cameras and as they pass each camera I can calculate the speed. They key is camera number and I am sending in a Vehicle object.
Now I am trying to retrieve variables from the Vehicle so I can do the calculations. I am getting the error in the loop in void calculateSpeeding(). The loop is only for testing at the moment.
package online.practice.averageSpeed;
import java.util.Arrays;
import java.util.HashMap;
public class Vehicle {
String licensePlates;
[Code] ....
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