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Handling an Array in Java (two columns)

For instance suppose I have the following String
String S = "5,a\n" +
"6,b\n" +
"9,a";
The format is always the same - one digit, then comma, then one character and then line end character.
For looping each row in String I use
for(String a : S.split("\\n")){}
I want to learn the character with highest amount, when grouped by character. For Instance, there is only one "b", so value is 6; whereas "a" has two lines, so its value is 5 + 9 = 14. Since 14 is maximum here, I want to find out "a" and 14 and save them in variables.

You can do something like below :
public static void main (String[] args) throws java.lang.Exception
{
String S = "5,a\n" +
"6,b\n" +
"9,a";
String[] lines = S.split("\\n");
Map<String, Integer> map = new HashMap<String, Integer>();
for( String t : lines )
{
String[] e = t.split(",");
Integer digit = Integer.parseInt(e[0]);
String c = e[1];
if ( map.get(c) != null )
{
Integer val = map.get(c);
val += digit;
map.put( c, val );
}
else
{
map.put( c, digit );
}
}
int max = 0;
String maxKey = null;
for ( String k : map.keySet() )
{
if ( map.get(k) > max )
{
max = map.get(k);
maxKey = k;
}
}
System.out.println("The maximum key is : " + maxKey );
System.out.println("The maximum value is : " + max );
}
Output is :
The maximum key is : a
The maximum value is : 14

Use a HashMap to store each pair, with the letter as the key. If the entry doesn't exist, put the first number. If it exists, get the entry and add the number, and then put the sum.
import java.util.HashMap;
import java.util.Map;
public class ParseTest {
public static void main(String[] args) {
String S = "5,a\n" + "6,b\n" + "9,a";
String maxKey = null;
int maxVal = 0;
Map<String, Integer> sums = new HashMap<>();
for (String a : S.split("\\n")) {
String[] split = a.split(",");
int value = Integer.parseInt(split[0]);
String key = split[1];
if (sums.containsKey(key)) {
sums.put(key, sums.get(key) + value);
} else {
sums.put(key, value);
}
if (sums.get(key) > maxVal) {
maxVal = sums.get(key);
maxKey = key;
}
}
System.out.println("Max key: " + maxKey + ", Sum: " + maxVal);
}
}

After finishing my answer, I found that many similar answers have been posted out :). Anyway, my solution:
public static void main(String[] args) {
String S = "5,a\n6,b\n9,a";
Map<String, Integer> map = new HashMap<String, Integer>();
String highestAmountChar = "";
int highestAmount = 0;
for (String str : S.split("\\n")) {
String[] amountChar = str.split(",");
if (map.get(amountChar[1]) == null) {
map.put(amountChar[1], Integer.parseInt(amountChar[0]));
} else {
map.put(amountChar[1], map.get(amountChar[1]) + Integer.parseInt(amountChar[0]));
}
if (highestAmount < map.get(amountChar[1])) {
highestAmount = map.get(amountChar[1]);
highestAmountChar = amountChar[1];
}
}
System.out.println("The character " + highestAmountChar + " has highest amount " + highestAmount);
}

You could use something like this without using HashMap or any collection for that matter
import java.util.Arrays;
public class Test {
public static void main(String args[]) {
String S = "5,a\n" +
"6,b\n" +
"9,a";
// Separate the string by number and letter
String[] separated = S.split("\\n");
// Create a new array to store the letters only
char[] letters = new char[separated.length];
// Write the letter
for (int i = 0; i < letters.length; i++) {
letters[i] = separated[i].charAt(2);
}
// Sort them haha
Arrays.sort(letters);
// And now find out which letter is repeated most
// Store the first letter
char previous = letters[0];
// Make it the most repeated one for now
char mostRepeated = letters[0];
int count = 1;
int maxCount = 1;
for (int i = 1; i < letters.length; i++) {
// since the array is sorted if the actual letter is the same as the previous one then keep counting
if (letters[i] == previous)
count++;
else {
if (count > maxCount) {
mostRepeated = letters[i - 1];
maxCount = count;
}
previous = letters[i];
count = 1;
}
}
char answer = count > maxCount ? letters[letters.length-1] : mostRepeated;
// Once you get the letter now just add all the numbers that goes with it
int sum = 0;
for (String s:separated) {
if (s.charAt(2) == answer) {
sum += Character.getNumericValue(s.charAt(0));
}
}
// Print the result by printing the letter and it sum
}
}

Java ArrayList<String> using for loop and overwriting itself

I'm trying to make my t String save to an ArrayList. but every time I run my program more than once it overwrites the previous data I want it to be a continuation. Creating the Array inside or out of the loop doesn't seem to help it just keeps rewriting over what is already there.
private void sets(ArrayList<Integer> save, int answer) {
String s = ", ";
String t = "";
for (int i = 0; i < 6; i += 1) {
t = t + String.valueOf(save.get(i)) + s;
}
for(int n = place ;n<1 ;){
ArrayList<String> message = new ArrayList<String>();
message.add(t);
place=place+1;
System.out.println(message);
return;
}
}

Move ArrayList<String> message = new ArrayList<String>(); to right after your class statement. Example:
public class xxxxx{
ArrayList<String> message = new ArrayList<String>();
//rest of your code
}

You can do that in two ways..
You can place the data structure at the beginning of the method sets and this obviously will have all the data in message lost once the method has exited.
private void sets(ArrayList<Integer> save, int answer) {
ArrayList<String> message = new ArrayList<String>();
String s = ", ";
String t = "";
for (int i = 0; i < 6; i += 1) {
t = t + String.valueOf(save.get(i)) + s;
}
for (int n = place; n < 1;) {
message.add(t);
place = place + 1;
System.out.println(message);
}
return;
}
Or you can declare a global variable that can always handle your data for as long as the program still executes.
private ArrayList<String> message = new ArrayList<String>();
private void sets(ArrayList<Integer> save, int answer) {
String s = ", ";
String t = "";
for (int i = 0; i < 6; i += 1) {
t = t + String.valueOf(save.get(i)) + s;
}
for (int n = place; n < 1;) {
message.add(t);
place = place + 1;
System.out.println(message);
}
return;
}
It all comes down to your requirements. #GOODLUCK

Creating a table in a for loop java

I have 2 arrays which values are words, each word in the first table is associated with a text (String), now each word from second table is showing how many times (int) is repeating in text (String). The expected table should to be like:
This is the code that I've written so far:
keyW = txtKeyword.getText();
search = textField.getText();
System.out.println("String for car = " + search);
System.out.println("String keyword = " + keyW);
btnUpload.setEnabled(false);
btnNewButton_1.setEnabled(false);
btnNewButton.setEnabled(false);
txtKeyword.setEnabled(false);
textField.setEditable(false);
//waitLabel.setVisible(true);
int iar = 0;
int item;
Map<String, Integer> dictionary = new HashMap<String, Integer>();
String[] searchArray = search.split(",");
String[] itemsFromArray1 = new String[searchArray.length];
//Keyword1 = ("Searched Key"+ "\r\n\t ");
//listKeys.add(Keyword1);
for (iar = 0; iar < searchArray.length; iar++) {
itemsFromArray1[iar] = searchArray[iar].trim();
Keyword1 = (searchArray[iar]);
//listKeys.add(Keyword1);
}
String[] items = keyW.split(",");
for (item = 0; item < searchArray.length; item++) {
WebDriver driver = new HtmlUnitDriver();
((HtmlUnitDriver) driver).setJavascriptEnabled(true);
driver.get("https://en.wikipedia.org/wiki/" + searchArray[item]);
tstr1 = driver.findElement(By.xpath("//*[#id='content']")).getText();
driver.quit();
String[] itemsFromArray = new String[items.length];
for (int i = 0; i < items.length; i++) {
itemsFromArray[i] = items[i].trim();
}
for (String string : itemsFromArray) {
int i = countWords(tstr1, string);
dictionary.put(searchArray[item].concat(string), i);
System.out.println("ARRAY " + dictionary);
}
}
private static int countWords(String tstr1, String string) {
tstr1 = tstr1.toLowerCase();
string = string.toLowerCase();
int posCount = 0;
String positive = string;
Pattern positivePattern = Pattern.compile(positive);
Matcher matcher = positivePattern.matcher(tstr1);
while (matcher.find()) {
posCount++;
}
return posCount;
}
I tried to achieve this with Map<String, Integer> dictionary = new HashMap<String, Integer>(); but the results (dictionary.put(searchArray[item], i);) are wrong. Can anyone give me an idea how to solve this. Thanks!
****UPDATE****
Now the results in the console is something like this:
ARRAY { boyanimal=4, catfree=18, catanimal=60, boyfree=2, catgender=0, boygender=6, windowfree=5}
ARRAY { boyanimal=4, catfree=18, catanimal=60, boyfree=2, windowanimal=4, catgender=0, boygender=6, windowfree=5}
ARRAY { boyanimal=4, catfree=18, catanimal=60, boyfree=2, windowanimal=4, catgender=0, boygender=6, windowgender=0, windowfree=5}
There are values that are repeting. How to make to show just like a table?

Try using this:
Map<String, Integer> tableMap = new HashMap<String, Integer>();
keep the key as:
tableMap.put("Word1-Search1",23);
Using this, you will always have a unique combination for each key.
I hope you don't want to store the data in a data structure? Instead you should use a 2 dimensional String array to store it.

Answering your latest update:
I think you're getting multiple copies because of this line.
dictionary.put(searchArray[item].concat(string), i);
I think the concat is being applied to the entire row of elements. I would use my debugger to analyze this and see what the value of searchArray[item] is and what the value of string is.

sub arraylist's size isn't correct

After hard searchig I still haven't found the proper answer for my question and there is it:
I have to write a java program that enters an array of strings and finds in it the largest sequence of equal elements. If several sequences have the same longest length, the program should print the leftmost of them. The input strings are given as a single line, separated by a space.
For example:
if the input is: "hi yes yes yes bye",
the output should be: "yes yes yes".
And there is my source code:
public static void main(String[] args) {
System.out.println("Please enter a sequence of strings separated by spaces:");
Scanner inputStringScanner = new Scanner(System.in);
String[] strings = inputStringScanner.nextLine().split(" ");
System.out.println(String.join(" ", strings));
ArrayList<ArrayList<String>> stringsSequencesCollection = new ArrayList<ArrayList<String>>();
ArrayList<String> stringsSequences = new ArrayList<String>();
stringsSequences.add(strings[0]);
for (int i = 1; i < strings.length; i++) {
if(strings[i].equals(strings[i - 1])) {
stringsSequences.add(strings[i]);
} else {
System.out.println(stringsSequences + " " + stringsSequences.size());
stringsSequencesCollection.add(stringsSequences);
stringsSequences.clear();
stringsSequences.add(strings[i]);
//ystem.out.println("\n" + stringsSequences);
}
if(i == strings.length - 1) {
stringsSequencesCollection.add(stringsSequences);
stringsSequences.clear();
System.out.println(stringsSequences + " " + stringsSequences.size());
}
}
System.out.println(stringsSequencesCollection.size());
System.out.println(stringsSequencesCollection.get(2).size());
System.out.println();
int maximalStringSequence = Integer.MIN_VALUE;
int index = 0;
ArrayList<String> currentStringSequence = new ArrayList<String>();
for (int i = 0; i < stringsSequencesCollection.size(); i++) {
currentStringSequence = stringsSequencesCollection.get(i);
System.out.println(stringsSequencesCollection.get(i).size());
if (stringsSequencesCollection.get(i).size() > maximalStringSequence) {
maximalStringSequence = stringsSequencesCollection.get(i).size();
index = i;
//System.out.println("\n" + index);
}
}
System.out.println(String.join(" ", stringsSequencesCollection.get(index)));
I think it should be work correct but there is a problem - the sub array list's count isn't correct: All the sub arrayList's size is 1 and for this reason the output is not correct. I don't understand what is the reason for this. If anybody can help me to fix the code I will be gratefull!

I think it is fairly straight forward just keep track of a max sequence length as you go through the array building sequences.
String input = "hi yes yes yes bye";
String sa[] = input.split(" ");
int maxseqlen = 1;
String last_sample = sa[0];
String longest_seq = last_sample;
int seqlen = 1;
String seq = last_sample;
for (int i = 1; i < sa.length; i++) {
String sample = sa[i];
if (sample.equals(last_sample)) {
seqlen++;
seq += " " + sample;
if (seqlen > maxseqlen) {
longest_seq = seq;
maxseqlen = seqlen;
}
} else {
seqlen = 1;
seq = sample;
}
last_sample = sample;
}
System.out.println("longest_seq = " + longest_seq);

Lots of issues.
First of all, when dealing with the last string of the list you are not actually printing it before clearing it. Should be:
if(i == strings.length - 1)
//...
System.out.println(stringsSequences + " " + stringsSequences.size());
stringsSequences.clear();
This is the error in the output.
Secondly, and most importantly, when you do stringsSequencesCollection.add you are adding an OBJECT, i.e. a reference to the collection. When after you do stringsSequences.clear(), you empty the collection you just added too (this is because it's not making a copy, but keeping a reference!). You can verify this by printing stringsSequencesCollection after the first loop finishes: it will contain 3 empty lists.
So how do we do this? First of all, we need a more appropriate data structure. We are going to use a Map that, for each string, contains the length of its longest sequence. Since we want to manage ties too, we'll also have another map that for each string stores the leftmost ending position of the longest sequence:
Map<String, Integer> lengths= new HashMap<>();
Map<String, Integer> indexes= new HashMap<>();
String[] split = input.split(" ");
lengths.put(split[0], 1);
indexes.put(split[0], 0);
int currentLength = 1;
int maxLength = 1;
for (int i = 1; i<split.length; i++) {
String s = split[i];
if (s.equals(split[i-1])) {
currentLength++;
}
else {
currentLength = 1;
}
int oldLength = lengths.getOrDefault(s, 0);
if (currentLength > oldLength) {
lengths.put(s, currentLength);
indexes.put(s, i);
}
maxLength = Math.max(maxLength, currentLength);
}
//At this point, youll have in lengths a map from string -> maxSeqLengt, and in indexes a map from string -> indexes for the leftmost ending index of the longest sequence. Now we need to reason on those!
Now we can just scan for the strings with the longest sequences:
//Find all strings with equal maximal length sequences
Set<String> longestStrings = new HashSet<>();
for (Map.Entry<String, Integer> e: lengths.entrySet()) {
if (e.value == maxLength) {
longestStrings.add(e.key);
}
}
//Of those, search the one with minimal index
int minIndex = input.length();
String bestString = null;
for (String s: longestStrings) {
int index = indexes.get(s);
if (index < minIndex) {
bestString = s;
}
}
System.out.println(bestString);

Below code results in output as you expected:
public static void main(String[] args) {
System.out.println("Please enter a sequence of strings separated by spaces:");
Scanner inputStringScanner = new Scanner(System.in);
String[] strings = inputStringScanner.nextLine().split(" ");
System.out.println(String.join(" ", strings));
List <ArrayList<String>> stringsSequencesCollection = new ArrayList<ArrayList<String>>();
List <String> stringsSequences = new ArrayList<String>();
//stringsSequences.add(strings[0]);
boolean flag = false;
for (int i = 1; i < strings.length; i++) {
if(strings[i].equals(strings[i - 1])) {
if(flag == false){
stringsSequences.add(strings[i]);
flag= true;
}
stringsSequences.add(strings[i]);
}
}
int maximalStringSequence = Integer.MIN_VALUE;
int index = 0;
List <String> currentStringSequence = new ArrayList<String>();
for (int i = 0; i < stringsSequencesCollection.size(); i++) {
currentStringSequence = stringsSequencesCollection.get(i);
System.out.println(stringsSequencesCollection.get(i).size());
if (stringsSequencesCollection.get(i).size() > maximalStringSequence) {
maximalStringSequence = stringsSequencesCollection.get(i).size();
index = i;
//System.out.println("\n" + index);
}
}
System.out.println(stringsSequences.toString());

LZW decoding miss the first code entry

I followed the Rosetta Java code implementation.
I tried do this LZW coding with my own Dictionary and not with the ASCII Dictionary which was used.
When I try with my own Dictioanry there is a problem about decoding... The result is wrong, because each of decoded word don't view the first 'a' letter.
The result have to be 'abraca abrac abra' and not 'braca brac bra'
I see the problem in decode() method at String act = "" + (char)(int)compressed.remove(0); This will remove all first 'a' letter.
But I don't have any ideas how can I modify this line...
For example if I use the String act = "";instead of above line... the coding will be very wrong, or use another command... I don't know how can I solve this little problem... Or maybe I am looking for on the bad way for the solution.
public class LZW {
public static List<Integer> encode(String uncompressed) {
Map<String,Integer> dictionary = DictionaryInitStringInt();
int dictSize = dictionary.size();
String act = "";
List<Integer> result = new ArrayList<Integer>();
for (char c : uncompressed.toCharArray()) {
String next = act + c;
if (dictionary.containsKey(next))
act = next;
else {
result.add(dictionary.get(act));
// Add next to the dictionary.
dictionary.put(next, dictSize++);
act = "" + c;
}
}
// Output the code for act.
if (!act.equals(""))
result.add(dictionary.get(act));
return result;
}
public static String decode(List<Integer> compressed) {
Map<Integer,String> dictionary = DictionaryInitIntString();
int dictSize = dictionary.size();
String act = "" + (char)(int)compressed.remove(0);
//String act = "";
String result = act;
for (int k : compressed) {
String entry;
if (dictionary.containsKey(k))
entry = dictionary.get(k);
else if (k == dictSize)
entry = act + act.charAt(0);
else
throw new IllegalArgumentException("Nincs ilyen kulcs: " + k);
result += entry;
dictionary.put(dictSize++, act + entry.charAt(0));
act = entry;
}
return result;
}
public static Map<String,Integer> DictionaryInitStringInt()
{
char[] characters = {'a','b','c','d','e','f','g','h','i','j', 'k','l','m','n',
'o','p','q','r','s','t','u','v','w','x','y','z',' ','!',
'?','.',','};
int charactersLength = characters.length;
Map<String,Integer> dictionary = new HashMap<String,Integer>();
for (int i = 0; i < charactersLength; i++)
dictionary.put("" + characters[i], i);
return dictionary;
}
public static Map<Integer,String> DictionaryInitIntString()
{
char[] characters = {'a','b','c','d','e','f','g','h','i','j', 'k','l','m','n',
'o','p','q','r','s','t','u','v','w','x','y','z',' ','!',
'?','.',','};
int charactersLength = characters.length;
Map<Integer,String> dictionary = new HashMap<Integer,String>();
for (int i = 0; i < charactersLength; i++)
dictionary.put(i,"" + characters[i]);
return dictionary;
}
public static void main(String[] args) {
List<Integer> compressed = encode("abraca abrac abra");
System.out.println(compressed);
String decodeed = decode(compressed);
// decodeed will be 'braca brac bra'
System.out.println(decodeed);
}
}

The rosetta example use
"" + (char) (int) compressed.remove(0);
because the first 256 entries of the dictionnary map exactly the 'char' values.
With a custom dictionnary this line should be:
String act = dictionary.get(compressed.remove(0));