Reformat a String array - java

I would like to re-format a String array based on condition. Say, the array
A = ["samsung", "chargers", "fast", "charging", "rapid", "high"]
int index = 1
Which means I will adjoin the items till index 1 with space and format the array. So, finally, it will be,
A = ["samsung chargers", "fast", "charging", "rapid", "high"]
For the index = 2, the output should be,
A = ["samsung chargers fast", "charging", "rapid", "high"]
I write the code that works, I try to find more concise (but not low performance) way.
StringBuilder builder = null;
..........
int fCount = ...
// format the array to match the string
// values = ["samsung", "chargers", "fast", "charging", "rapid", "high"]
builder = new StringBuilder();
String formated = "";
for (int i = 0; i <= fCount; i++) {
builder.append(values[i]).append(" ");
}
formated = builder.toString().trim();
String[] fVaues = new String[values.length - fCount];
fVaues[0] = formated;
for (int i = 1; i < fVaues.length; i++) {
fVaues[i] = values[i+1];
}
What is the simple way to accomplish it?

This method does the same thing:
static String[] joinUntil(String[] original, int until) {
return Stream.concat(
Stream.of(String.join(" ", Arrays.copyOf(original, until))),
Arrays.stream(Arrays.copyOfRange(original, until, original.length))
).toArray(String[]::new);
}

private static List<String> reFormat(List<String> lst, int index){
String joined = String.join(" ", lst.subList(0, index + 1));
List<String> res = new ArrayList<String>();
res.add(joined);
res.addAll(lst.subList(index + 1, lst.size()));
return res;
}

You could just loop over it, adding the Strings to a second array:
String[] b = new String[a.length - index];
String tmp = a[0];
for(int i = 1; i < a.length; i++) {
if(i <= index) {
tmp += " " + a[i];
if(i == index) {
b[i - index] = tmp;
}
}
else {
b[i - index] = a[i];
}
}

Related

Remove null from unused space of StringArray when converting to a string in Java

I was working on a Java coding problem and encountered the following issue.
Input: A String -> "Code"
Output Expected: A string -> CCoCodCode
My Code snippet: (Note: In comments I have written what I expect upon passing the string)
public String stringSplosion(String str) { // string Say 'Code'
String join = "", values = "";
String gotIt = "";
int n = str.length(); // 4
int size = 0;
for (int i = n; i >= 1; i--) {
size = size + n; // 4+3+2+1=10
}
String[] result = new String[size];
for (int i = 0; i < str.length(); i++) {
values = str.substring(i, i + 1);
join = join + values;
result[i] = join;
}
for (String s : result) {
gotIt = gotIt + s;
}
return gotIt; // Expected output: CCoCodCode
}
Output I am getting:
CCoCodCodenullnullnullnullnullnullnullnullnullnullnullnull
Why is null getting stored although I have reduced the size and how can I remove it?
NOTE: I need to solve this using arrays. I know it is much easier using List.
If you want to keep the current structure of your code, get rid of the first for loop.
And create String[] array = new String[n]
public static String stringSplosion(String str) { // string Say 'Code'
String join = "", values = "";
String gotIt = "";
int n = str.length(); // 4
String[] result = new String[n]; //you want your String array to contain 4 strings
for (int i = 0; i < str.length(); i++) {
values = str.substring(i, i + 1);
join = join + values;
result[i] = join;
}
for (String s : result) {
gotIt = gotIt + s;
}
return gotIt; // Expected output: CCoCodCode
}
public class Answer {
public static String answer(String input){
StringBuilder sb = new StringBuilder(((input.length() + 1) * input.length()) / 2);
for (int i = 1; i <= input.length(); i++) {
sb.append(input.substring(0, i));
}
return sb.toString();
}
public static void main(String[] args) {
System.out.println(answer("Code"));
}
}
Below statements are not required:
int size = 0;
for (int i = n; i >= 1; i--) {
size = size + n; // 4+3+2+1=10
}
You just need to change the array size from
String[] result = new String[size];
to
String[] result = new String[n];
for your program to give the expected output.
If I understand ur problem correctly to print the pattern then u can use below code,
public String printPattern(String input){
//Holds the iteration value by index
int previous=0;
//It holds the result characters
String result=null;
StringBuilder strBuilder=new StringBuilder();
//first loop to iterate only till input string length
for(int i=0;i<input.length();i++){
//checking iteration lenght with input string length
if(previous<input.length()){
//incrementing iteration for reading characters from input string
previous++;
//main loop for previous iteration value check and iterate
for(int j=0;j<previous;j++){
//converting string to Character array
char a []=input.toCharArray();
//using string builder to build the string from characters
strBuilder.append((a[j]));
//setting the value to stringbuilder by converting it in string
result=strBuilder.toString();
}
}
}
return result;
}
Size should be the length of string. Code's length is 4. Code will produce {C, Co, Cod, Code}.
public String stringSplosion(String str) { // string Say 'Code'
String join = "", values = "";
String gotIt = "";
int n = str.length(); // 4
String[] result = new String[n];
for (int i = 0; i < str.length(); i++) {
values = str.substring(i, i + 1);
join = join + values;
result[i] = join;
}
System.out.println(Arrays.toString(result));
for (String s : result) {
gotIt = gotIt + s;
}
return gotIt; // Expected output: CCoCodCode
}
String input = "Code";
String output[] = IntStream.range(0, input.length()+1)
.mapToObj(i -> input.substring(0, i))
.toArray(String[]::new);

How to convert reminder int value to string (Characters)

How to convert int value into string means my string will be 42646 character its mod 42600 how to show and print this character and how?
int count = image_length.length(); //count=42646
System.out.println(count);
int mod = count % length; //46
int rem = count - mod; //42600
String rem_value = String.valueOf(rem);
// I want to get string through reminder value 42600 & how
String[] split = rem_value.split("[^a-zA-Z/]", length);
getSaltString();
photoName = randStr + "_IMG.jpg";
StringBuilder stringBuilder = new StringBuilder();
for (int i = 0; i < split.length; i++) {
url_part = String.valueOf(stringBuilder.append(split[i]));
new RegisterImageThread(ActivityRegisterUploadPhoto.this).execute(photoName, url_part + i);
}
new RegisterImageThread(ActivityRegisterUploadPhoto.this).execute(photoName, url_part+rem_value);
So you want to split the numeric String "42600" to an array right?
Replace the line:
String[] split = rem_value.split("[^a-zA-Z/]", length);
to something like this:
String rem_value = "42600"; //your rem_value
int[] split = new int[rem_value.length()];
for (int i = 0; i < rem_value.length(); i++) {
split[i] = Character.getNumericValue(rem_value.charAt(i));
}
//print the result
Arrays.stream(split).forEach(s -> System.out.println(s));

Convert comma separated string to array without string split?

Using Java, how would I convert "Paul, John, Ringo" to
Paul
John
Ringo
But while using a loop that searches for the commas and pulls out the words between them? I can't use anything like string split, strictly a loop and pretty simple java. Thanks!
String str = "Paul, John, Ringo";
List<String> words = new ArrayList<String>();
int cIndex = 0;
for (int i = 0; i < str.length(); i++) {
if (str.charAt(i) == ',') {
String temp = str.substring(cIndex, i).trim();
cIndex = i + 1;
words.add(temp);
}
}
String temp = str.substring(str.lastIndexOf(',')+1,str.length()).trim();
words.add(temp);
List<String> list = new List<String>();
String text = "your, text, here";
int indexTraversed = 0;
while(true){
int i = text.indexOf(",", indexTraversed);
if(i<0) break;
list.add(text.substring(indexTraversed, i));
indexTraversed += i + 1;
}
String[] array = list.toArray();
and if you can't use List :
String[] list = new String[100];
int counter = 0;
String text = "your, text, here";
int indexTraversed = 0; // declaring and assigning var
while(true){
int i = text.indexOf(",", indexTraversed);
if(i<0) break;
list.add(text.substring(indexTraversed, i));
indexTraversed += i + 1;
counter ++;
}
Then read the list array until counter.

My findCombos method does not work, How to remove characters from java character array

I am making a method which will return a String[] containing valid combinations of words that differ by one letter. The method takes as String array containing a dictionary of words as the first parameter, and two other strings containing the words one and two respectively as the second and third parameters.
Here is my method:
public static String[] findCombos(String[] dict, String a, String b){
char[] wordA = a.toCharArray();
char[] wordB = b.toCharArray();
int length = wordA.length;
List<String> validCombos = new ArrayList<String>();
Arrays.sort(dict);
//wordA
for(int i = 0; i<length; i++){
char tmp = wordA[i];
wordA[i] = 0;
String tmpWordA = new String(wordA).trim();
//tmpWordA = tmpWordA + wordA.toString().trim();
if(Arrays.binarySearch(dict, tmpWordA) >= 0){
int lengthb = wordB.length;
String tmpWordB = new String(wordB).trim();
//tmpWordB = tmpWordB + wordB.toString();
for(int j = 0; j<lengthb; j++){
tmpWordB = new StringBuffer(tmpWordB).insert(j ,tmp).toString();
if(Arrays.binarySearch(dict, tmpWordB) >= 0){
validCombos.add(tmpWordA + "\\t" + tmpWordB);//combo found
}else{
wordA[i] = tmp;
}
}
}else{
wordA[i] = tmp;
}
}
//wordB
int lengthb = b.length();
for(int i = 0; i<lengthb; i++){
char tmp = wordB[i];
wordB[i] = 0;
String tmpWordB = new String(wordB).trim();
//tmpWordB = tmpWordB + wordB.toString().trim();
if(Arrays.binarySearch(dict, tmpWordB) >= 0){
int lengtha = a.length();
String tmpWordA = new String(wordA).trim();
//tmpWordA = tmpWordA + wordA.toString();
for(int j = 0; j< lengtha; j++){
tmpWordA = new StringBuffer(tmpWordA).insert(j, tmp).toString();
if(Arrays.binarySearch(dict, tmpWordA) >= 0){
validCombos.add(tmpWordA + "\\t" + tmpWordB);//combo found
}else{
wordB[i] = tmp;
}
}
}else{
wordB[i] = tmp;
}
}
String[] res = validCombos.toArray(new String[0]);
return res;
}
The array has been sorted and I am certain that the element in question is in the array, however the search keeps returning a negative number and automatically branching to the else clause. Any ideas? Here is a link to the dictionary:
Dictionary - PasteBin
You are not removing the character at index i, you are replacing the character at index i with 0, that false assumption breaks your algorithm.
Delete a character by index from a character array with StringBuilder
String mystring = "inflation != stealing";
char[] my_char_array = mystring.toCharArray();
StringBuilder sb = new StringBuilder();
sb.append(mystring);
sb.deleteCharAt(10);
my_char_array = sb.toString().toCharArray();
System.out.println(my_char_array); //prints "inflation = stealing"
The above code removes the exclamation mark from the character array.
Roll your own java function to remove a character from a character array:
String msg = "johnny can't program, he can only be told what to type";
char[] mychararray = msg.toCharArray();
mychararray = remove_one_character_from_a_character_array_in_java(mychararray, 21);
System.out.println(mychararray);
public char[] remove_one_character_from_a_character_array_in_java(
char[] original,
int location_to_remove)
{
char[] result = new char[original.length-1];
int last_insert = 0;
for (int i = 0; i < original.length; i++){
if (i == location_to_remove)
i++;
result[last_insert++] = original[i];
}
return result;
}
//The above method prints the message with the index removed.
Source:
https://stackoverflow.com/a/11425139/445131

Fancy looping in Java

I have a problem wherein I have two strings, the length of one of which I will know only upon execution of my function. I want to write my function such that it would take these two stings and based upon which one is longer, compute a final string as under -
finalString = longerStringChars1AND2
+ shorterStringChar1
+ longerStringChars3and4
+ shorterStringChar2
+ longerStringChars5AND6
...and so on till the time the SHORTER STRING ENDS.
Once the shorter string ends, I want to append the remaining characters of the longer string to the final string, and exit. I have written some code, but there is too much looping for my liking. Any suggestions?
Here is the code I wrote - very basic -
public static byte [] generateStringToConvert(String a, String b){
(String b's length is always known to be 14.)
StringBuffer stringToConvert = new StringBuffer();
int longer = (a.length()>14) ? a.length() : 14;
int shorter = (longer > 14) ? 14 : a.length();
int iteratorForLonger = 0;
int iteratorForShorter = 0;
while(iteratorForLonger < longer) {
int count = 2;
while(count>0){
stringToConvert.append(b.charAt(iteratorForLonger));
iteratorForLonger++;
count--;
}
if(iteratorForShorter < shorter && iteratorForLonger >= longer){
iteratorForLonger = 0;
}
if(iteratorForShorter<shorter){
stringToConvert.append(a.charAt(iteratorForShorter));
iteratorForShorter++;
}
else{
break;
}
}
if(stringToConvert.length()<32 | iteratorForLonger<b.length()){
String remainingString = b.substring(iteratorForLonger);
stringToConvert.append(remainingString);
}
System.out.println(stringToConvert);
return stringToConvert.toString().getBytes();
}
You can use StringBuilder to achieve this. Please find below source code.
public static void main(String[] args) throws InterruptedException {
int MAX_ALLOWED_LENGTH = 14;
String str1 = "yyyyyyyyyyyyyyyy";
String str2 = "xxxxxx";
StringBuilder builder = new StringBuilder(MAX_ALLOWED_LENGTH);
builder.append(str1);
char[] shortChar = str2.toCharArray();
int index = 2;
for (int charCount = 0; charCount < shortChar.length;) {
if (index < builder.length()) {
// insert 1 character from short string to long string
builder.insert(index, shortChar, charCount, 1);
}
// 2+1 as insertion index is increased after after insertion
index = index + 3;
charCount = charCount + 1;
}
String trimmedString = builder.substring(0, MAX_ALLOWED_LENGTH);
System.out.println(trimmedString);
}
Output
yyxyyxyyxyyxyy
String one = "longwordorsomething";
String two = "short";
String shortString = "";
String longString = "";
if(one.length() > two.length()) {
shortString = two;
longString = one;
} else {
shortString = one;
longString = two;
}
StringBuilder newString = new StringBuilder();
int j = 0;
for(int i = 0; i < shortString.length(); i++) {
if((j + 2) < longString.length()) {
newString.append(longString.substring(j, j + 2));
j += 2;
}
newString.append(shortString.substring(i, i + 1));
}
// Append last part
newString.append(longString.substring(j));
System.out.println(newString);

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