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How to sort a array that contains special characters alphabetically?

I am looking for code that produces the following output in standard output from the following string prepared according to a certain format.
Assumptions and rules:
Each letter is used 2 times in the given string and the letters between the same 2 letters are to be considered child letters.
The given string is always given in proper format. The string format
does not need to be checked.
Example:
Input : abccbdeeda
Expected output:
a
--b
----c
--d
----e
Explanation: since the 2 letters "b" occur between the letters "a", the letter b takes 2 hyphens (--b)
Attempt
public static void main(String[] args) {
String input = "abccbdeeda";
System.out.println("input: " + input);
String[] strSplit = input.split("");
String g = "";
String h = "-";
ArrayList<String> list = new ArrayList<String>();
int counter = 1;
boolean secondNumber;
list.add(strSplit[0]);
int dual = 0;
for (int i = 1; i < strSplit.length; i++) {
secondNumber = list.contains(strSplit[i]);
if ((secondNumber)) {
counter--;
dual = counter * 2;
for (int f = 0; f < dual; f++) {
strSplit[i] = h.concat(strSplit[i]);
}
g = "";
dual = 0;
} else {
list.add(strSplit[i]);
counter++;
}
}
Arrays.sort(strSplit);
for (int p = 0; p < strSplit.length; p++) {
System.out.println(strSplit[p]);
}
}
input: abccbdeeda
My output:
----c
----e
--b
--d
a
I wasn't able to sort the output alphabetically. How can I sort alphabetically with those hyphen characters in them?

This task is nicely done with the help of a stack. If the current character is equal to the top of the stack, then the character is closed and can be removed, otherwise we met it for the first time and it must be added to the stack and the resulting string by adding before it stack.size() * 2 dashes.
When we have completely traversed the string we can sort the resulting string.
public static void main(String[] args) {
Stack<Character> stack = new Stack<>();
String string = "abccbdeeda";
StringBuilder result = new StringBuilder();
for(int i = 0; i < string.length(); i++) {
char curChar = string.charAt(i);
if(!stack.isEmpty() && curChar == stack.peek()) {
stack.pop();
} else {
result.append("-".repeat(stack.size() * 2)).append(curChar).append(" ");
stack.add(curChar);
}
}
System.out.println(result);
System.out.println(Arrays.toString(Arrays.stream(result.toString().split(" ")).sorted().toArray()));
}
Output
a --b ----c --d ----e
[----c, ----e, --b, --d, a]

You can go through the strSplit array and extract the charactors in each element to a separate list/array. To check whether the array element contains a letter you can write a regular expression.
Ex: private final Pattern x = Pattern.compile("[a-z]");
Write a separate method to match the patern to each element in the strSplit array. This method will return the charactor in your input string.
private String findCharactor(final StringBuilder element) {
final Matcher matcher = x.matcher(element);
if (matcher.find()) {
final int matchIndex = matcher.start(); //this gives the index of the char in the string
return element.substring(matchIndex);
}
}
Add these returned charactors to a separate array and sort it using sorting function.

Suppose your result list is:
List<String> resultList = Arrays.asList("----c", "----e", "--b", "--d", "a");
You can sort it alphabetically by a single line:
Collections.sort(resultList, (o1, o2) -> new StringBuilder(o1).reverse().toString().compareTo(new StringBuilder(o2).reverse().toString()));

You can use recursion for a depth-first traversal (preorder):
public static String dfs(String string, String prefix) {
if (string.length() == 0) return "";
int i = string.indexOf(string.charAt(0), 1);
return prefix + string.charAt(0) + "\n" // current
+ dfs(string.substring(1, i), prefix + "--") // all nested
+ dfs(string.substring(i + 1), prefix); // all siblings
}
Example call:
public static void main(String[] args) {
System.out.println(dfs("abccbdeeda", ""));
}

Split Word into Two and Check Existence in Comma Separated String Sequence

I have a string array for example:
new String[] = {"powerhouse", "p, pow, power, house, pose, poser"};
My goal is to split the first entry in the array in this case powerhouse into any two words and check them against the second entry, which serves as a dictionary of words.
Here's my implementation so far:
public static String[] convertWordsToArray(String input){
String[] wordArr = null;
wordArr = input.split(",");
return wordArr;
}
public static String splitEm(String[] strArr) {
String fw = strArr[0];
String sw = strArr[1];
String[] arrOne = convertWordsToArray(fw);
System.out.println(arrOne.length);
String[] dict = convertWordsToArray(sw);
System.out.println(dict.length);
for(int i = 0; i < dict.length - 1; i++) {
String mWord = fw.split(i, i + 1);
System.out.println(mWord);
}
// Edit Starts Here, tried to substring it but nothing prints in log
for(int i = 0; i < arrOne.length; i++) {
String mWord = fw.substring(0, i);
System.out.println(mWord);
}
return ""; // empty for now
}
I am stuck at the part where the first word has to be split. Should I use two loops, one for the first word and the other for the dictionary? I know that somehow the dictionary has to be converted to a list or array list to avail the .contains() method. How do I go about this? Thanks.

If anyone want the solution for PHP language, then you can use below code:
function ArrayChallenge($strArr) {
$dictWords = explode( ',', $strArr[1] );
$strLength = strlen($strArr[0]);
$output = 'not possible';
for( $i = 1; $i < $strLength; $i++ ){
$firstStr = substr($strArr[0], 0, $i);
$lastStr = substr($strArr[0], $i, $strLength);
if ( in_array( $firstStr, $dictWords ) && in_array( $lastStr, $dictWords ) ) {
$output = $firstStr . ',' . $lastStr;
break;
}
}
return $output;
}

Do you need something like this?
String s = "powerhouse";
List<String> list = new ArrayList<String>();
for(int i = 0; i < s.length(); i++){
for(int j = i+1; j <= s.length(); j++){
list.add(s.substring(i,j));
}
}
System.out.println(list);
I assume you need something like below:
Split second string at each , or even better using regex to trim
spaces before or after ,
check if each part of the splited entry fro above point is made of
only the chars contained in the first entry of your input
example
public static void main(String args[]) {
String[] test1 = {"powerhouse", "p, pow, power, house, pose, poser"};
String[] test2 = {"powerhouse", "p, xyz, power, house, pose, poser"};
System.out.println(check(test1));
System.out.println(check(test2));
}
static boolean check(String[] input){
String firstEntry = input[0];
String[] dictionary = input[1].split("\\s*,\\s*");
for(int i = 0; i < dictionary.length; i++){
if(!dictionary[i].matches("["+firstEntry+"]+")){
return false;
}
}
return true;
}
this will print true for the first case and false for the second as "xyz" is not a valid subpart/substring according to your discription

Try this :
public class Stack {
public static void main(String[] args) {
String[] str = {"powerhouse", "p, pow, power, house, pose, poser"};
String firstPart = str[0];
String secondPart = str[1];
boolean contain = isContain(firstPart, secondPart);
System.out.println(contain);
}
private static boolean isContain(String firstPart, String secondPart) {
for (int i = 0; i < firstPart.length(); i++) {
String firstWord = firstPart.substring(0, i);
String secondWord = firstPart.substring(i, firstPart.length());
List<String> strings = Arrays.asList(secondPart.trim().split("\\s*,\\s*"));
if (strings.contains(firstWord) && strings.contains(secondWord)) return true; if you want to check both words use this
//if (strings.contains(firstWord) || strings.contains(secondWord)) return true; if you want to check any(one) word from two words use this
}
return false;
}
}

Sorting an array of strings [duplicate]

This question already has an answer here:
Remove a common word from each string value in an array
(1 answer)
Closed 6 years ago.
I have an array of Strings that contains: Extra Water, Juice, and Extra Milk, so I am wondering how would I get rid of the extras and use the only second word in the string so that the expected output is Water, Juice, and Milk.

If all you want to do is remove a specific substring then:
String[] array = {"Extra Water", "Juice", "Extra Milk"};
array = Arrays.stream(array).map(s-> s.replaceAll("Extra", "")).toArray();
This uses Java 8 streams but you could do it just as simply with iteration.

Use String.split(' ') to split the string by a space, then check the result to see if the string length == 2. If so, then take the second element of the array, otherwise the first.
for( int i = 0; i < array.length; i++ ) {
String[] parts = array[i].split(' ');
if( parts.length == 2 ) {
array[i] = parts[1];
}
}
EDIT: If you want to remove all duplicate words, you could do the following using two passes over the array:
// Pass 1 -- find all duplicate words
Set<String> wordSet = new HashSet<>();
Set<String> duplicateSet = new HashSet<>();
for (int i = 0; i < array.length; i++) {
String[] parts = array[i].split(" ");
for (String part : parts) {
if (!wordSet.contains(part)) {
// Haven't seen this word before
wordSet.add(part);
} else {
// This word is a duplicate word
if (!duplicateSet.contains(part)) {
duplicateSet.add(part);
}
}
}
}
// Pass 2 -- remove all words that are in the duplicate set
for (int i = 0; i < array.length; i++) {
String[] parts = array[i].split(" ");
String dedupedString = "";
for (String part : parts) {
if (!duplicateSet.contains(part)) {
dedupedString += part + " ";
}
}
array[i] = dedupedString;
}

Simply you need to iterate over each element of the array and replace the "Extra" in each element of the array and then trim the white spaces.
String[] array = {"Extra Water", "Juice", "Extra Milk"};
for (int i = 0; i < array.length; i++) {
array[i] = array[i].replace("Extra", "").trim();
}
for (String each : array) {
System.out.println(each);
}

Tokenize method: Split string into array

I've been really struggling with a programming assignment. Basically, we have to write a program that translates a sentence in English into one in Pig Latin. The first method we need is one to tokenize the string, and we are not allowed to use the Split method usually used in Java. I've been trying to do this for the past 2 days with no luck, here is what I have so far:
public class PigLatin
{
public static void main(String[] args)
{
String s = "Hello there my name is John";
Tokenize(s);
}
public static String[] Tokenize(String english)
{
String[] tokenized = new String[english.length()];
for (int i = 0; i < english.length(); i++)
{
int j= 0;
while (english.charAt(i) != ' ')
{
String m = "";
m = m + english.charAt(i);
if (english.charAt(i) == ' ')
{
j++;
}
else
{
break;
}
}
for (int l = 0; l < tokenized.length; l++) {
System.out.print(tokenized[l] + ", ");
}
}
return tokenized;
}
}
All this does is print an enormously long array of "null"s. If anyone can offer any input at all, I would reallllyyyy appreciate it!
Thank you in advance
Update: We are supposed to assume that there will be no punctuation or extra spaces, so basically whenever there is a space, it's a new word

If I understand your question, and what your Tokenize was intended to do; then I would start by writing a function to split the String
static String[] splitOnWhiteSpace(String str) {
List<String> al = new ArrayList<>();
StringBuilder sb = new StringBuilder();
for (char ch : str.toCharArray()) {
if (Character.isWhitespace(ch)) {
if (sb.length() > 0) {
al.add(sb.toString());
sb.setLength(0);
}
} else {
sb.append(ch);
}
}
if (sb.length() > 0) {
al.add(sb.toString());
}
String[] ret = new String[al.size()];
return al.toArray(ret);
}
and then print using Arrays.toString(Object[]) like
public static void main(String[] args) {
String s = "Hello there my name is John";
String[] words = splitOnWhiteSpace(s);
System.out.println(Arrays.toString(words));
}

If you're allowed to use the StringTokenizer Object (which I think is what the assignment is asking, it would look something like this:
StringTokenizer st = new StringTokenizer("this is a test");
while (st.hasMoreTokens()) {
System.out.println(st.nextToken());
}
which will produce the output:
this
is
a
test
Taken from here.
The string is split into tokens and stored in a stack. The while loop loops through the tokens, which is where you can apply the pig latin logic.

Some hints for you to do the "manual splitting" work.
There is a method String#indexOf(int ch, int fromIndex) to help you to find next occurrence of a character
There is a method String#substring(int beginIndex, int endIndex) to extract certain part of a string.
Here is some pseudo-code that show you how to split it (there are more safety handling that you need, I will leave that to you)
List<String> results = ...;
int startIndex = 0;
int endIndex = 0;
while (startIndex < inputString.length) {
endIndex = get next index of space after startIndex
if no space found {
endIndex = inputString.length
}
String result = get substring of inputString from startIndex to endIndex-1
results.add(result)
startIndex = endIndex + 1 // move startIndex to next position after space
}
// here, results contains all splitted words

String english = "hello my fellow friend"
ArrayList tokenized = new ArrayList<String>();
String m = "";
int j = 0; //index for tokenised array list.
for (int i = 0; i < english.length(); i++)
{
//the condition's position do matter here, if you
//change them, english.charAt(i) will give index
//out of bounds exception
while( i < english.length() && english.charAt(i) != ' ')
{
m = m + english.charAt(i);
i++;
}
//add to array list if there is some string
//if its only ' ', array will be empty so we are OK.
if(m.length() > 0 )
{
tokenized.add(m);
j++;
m = "";
}
}
//print the array list
for (int l = 0; l < tokenized.size(); l++) {
System.out.print(tokenized.get(l) + ", ");
}
This prints, "hello,my,fellow,friend,"
I used an array list since at the first sight the length of the array is not clear.

How to split string at every nth occurrence of character in Java

I would like to split a string at every 4th occurrence of a comma ,.
How to do this? Below is an example:
String str = "1,,,,,2,3,,1,,3,,";
Expected output:
array[0]: 1,,,,
array[1]: ,2,3,,
array[2]: 1,,3,,
I tried using Google Guava like this:
Iterable<String> splitdata = Splitter.fixedLength(4).split(str);
output: [1,,,, ,,2,, 3,,1, ,,3,, ,]
I also tried this:
String [] splitdata = str.split("(?<=\\G.{" + 4 + "})");
output: [1,,,, ,,2,, 3,,1, ,,3,, ,]
Yet this is is not the output I want. I just want to split the string at every 4th occurrence of a comma.
Thanks.

Take two int variable. One is to count the no of ','. If ',' occurs then the count will move. And if the count is go to 4 then reset it to 0. The other int value will indicate that from where the string will be cut off. it will start from 0 and after the first string will be detected the the end point (char position in string) will be the first point of the next. Use the this start point and current end point (i+1 because after the occurrence happen the i value will be incremented). Finally add the string in the array list. This is a sample code. Hope this will help you. Sorry for my bad English.
String str = "1,,,,,2,3,,1,,3,,";
int k = 0;
int startPoint = 0;
ArrayList<String> arrayList = new ArrayList<>();
for (int i = 0; i < str.length(); i++)
{
if (str.charAt(i) == ',')
{
k++;
if (k == 4)
{
String ab = str.substring(startPoint, i+1);
System.out.println(ab);
arrayList.add(ab);
startPoint = i+1;
k = 0;
}
}
}

Here's a more flexible function, using an idea from this answer:
static List<String> splitAtNthOccurrence(String input, int n, String delimiter) {
List<String> pieces = new ArrayList<>();
// *? is the reluctant quantifier
String regex = Strings.repeat(".*?" + delimiter, n);
Matcher matcher = Pattern.compile(regex).matcher(input);
int lastEndOfMatch = -1;
while (matcher.find()) {
pieces.add(matcher.group());
lastEndOfMatch = matcher.end();
}
if (lastEndOfMatch != -1) {
pieces.add(input.substring(lastEndOfMatch));
}
return pieces;
}
This is how you call it using your example:
String input = "1,,,,,2,3,,1,,3,,";
List<String> pieces = splitAtNthOccurrence(input, 4, ",");
pieces.forEach(System.out::println);
// Output:
// 1,,,,
// ,2,3,,
// 1,,3,,
I use Strings.repeat from Guava.

try this also, if you want result in array
String str = "1,,,,,2,3,,1,,3,,";
System.out.println(str);
char c[] = str.toCharArray();
int ptnCnt = 0;
for (char d : c) {
if(d==',')
ptnCnt++;
}
String result[] = new String[ptnCnt/4];
int i=-1;
int beginIndex = 0;
int cnt=0,loopcount=0;
for (char ele : c) {
loopcount++;
if(ele==',')
cnt++;
if(cnt==4){
cnt=0;
result[++i]=str.substring(beginIndex,loopcount);
beginIndex=loopcount;
}
}
for (String string : result) {
System.out.println(string);
}

This work pefectly and tested in Java 8
public String[] split(String input,int at){
String[] out = new String[2];
String p = String.format("((?:[^/]*/){%s}[^/]*)/(.*)",at);
Pattern pat = Pattern.compile(p);
Matcher matcher = pat.matcher(input);
if (matcher.matches()) {
out[0] = matcher.group(1);// left
out[1] = matcher.group(2);// right
}
return out;
}
//Ex: D:/folder1/folder2/folder3/file1.txt
//if at = 2, group(1) = D:/folder1/folder2 and group(2) = folder3/file1.txt

The accepted solution above by Saqib Rezwan does not add the leftover string to the list, if it divides the string after every 4th comma and the length of the string is 9 then it will leave the 9th character, and return the wrong list.
A complete solution would be :
private static ArrayList<String> splitStringAtNthOccurrence(String str, int n) {
int k = 0;
int startPoint = 0;
ArrayList<String> list = new ArrayList();
for (int i = 0; i < str.length(); i++) {
if (str.charAt(i) == ',') {
k++;
if (k == n) {
String ab = str.substring(startPoint, i + 1);
list.add(ab);
startPoint = i + 1;
k = 0;
}
}
// if there is no comma left and there are still some character in the string
// add them to list
else if (!str.substring(i).contains(",")) {
list.add(str.substring(startPoint));
break;
}
}
return list;
}
}