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Code Works in IntelliJ but Not in Hackerrank Editor

I'm doing this question on hackerrank: https://www.hackerrank.com/challenges/ctci-bubble-sort/problem?h_l=interview&playlist_slugs%5B%5D=interview-preparation-kit&playlist_slugs%5B%5D=sorting
I wrote the solution in intellij, and it gives me the correct output there, but when I copied it over to the hackerrank ide, it gave me an error.
This is the code I'm talking about:
import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.function.*;
import java.util.regex.*;
import java.util.stream.*;
import static java.util.stream.Collectors.joining;
import static java.util.stream.Collectors.toList;
class Results {
/*
* Complete the 'countSwaps' function below.
*
* The function accepts INTEGER_ARRAY a as parameter.
*/
public static void countSwaps(List<Integer> a) {
int count = 0;
boolean flag = false;
while (!flag) {
flag = true;
for (int i = 0; i < a.size() - 1; i++) {
if (a.get(i) > a.get(i + 1)) {
int temp = a.get(i);
a.set(i, a.get(i + 1));
a.set(i + 1, temp);
flag = false;
count++;
}
}
}
System.out.println(String.format(
"Array is sorted in %d swaps.%n" +
"First Element: %d%n" +
"Last Element: %d%n",
count,
a.get(0),
a.get(a.size() - 1)));
}
public static class Solution {
public static void main(String[] args) throws IOException {
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
int n = Integer.parseInt(bufferedReader.readLine().trim());
List<Integer> a = Stream.of(bufferedReader.readLine().replaceAll("\\s+$", "").split(" "))
.map(Integer::parseInt)
.collect(toList());
Results.countSwaps(a);
bufferedReader.close();
}
}
}
This is the error: could not find or load main class solution.
Do you have any idea why I'm getting this error here? How could I fix it.

You have put the Solution class within your Result class. HackerRank wants you to put the Solution class as its own class, like this:
import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.function.*;
import java.util.regex.*;
import java.util.stream.*;
import static java.util.stream.Collectors.joining;
import static java.util.stream.Collectors.toList;
class Results {
/*
* Complete the 'countSwaps' function below.
*
* The function accepts INTEGER_ARRAY a as parameter.
*/
public static void countSwaps(List<Integer> a) {
int count = 0;
boolean flag = false;
while (!flag) {
flag = true;
for (int i = 0; i < a.size() - 1; i++) {
if (a.get(i) > a.get(i + 1)) {
int temp = a.get(i);
a.set(i, a.get(i + 1));
a.set(i + 1, temp);
flag = false;
count++;
}
}
}
System.out.println(String.format(
"Array is sorted in %d swaps.%n" +
"First Element: %d%n" +
"Last Element: %d%n",
count,
a.get(0),
a.get(a.size() - 1)));
}
}
class Solution {
public static void main(String[] args) throws IOException {
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
int n = Integer.parseInt(bufferedReader.readLine().trim());
List<Integer> a = Stream.of(bufferedReader.readLine().replaceAll("\\s+$", "").split(" "))
.map(Integer::parseInt)
.collect(toList());
Results.countSwaps(a);
bufferedReader.close();
}
}
Please, check your code syntax and read the error that the IDE gives you. It did explicitly tell you that Error: Could not find or load main class Solution and just a quick check on the automatic indentation would have shown you the issue.

Online Coding contest platforms generally require you to adhere to certain rules for submissions.
See: Sample Problem Statement
import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.function.*;
import java.util.regex.*;
import java.util.stream.*;
import static java.util.stream.Collectors.joining;
import static java.util.stream.Collectors.toList;
public class Solution
{
/*
* Complete the 'countSwaps' function below.
*
* The function accepts INTEGER_ARRAY a as parameter.
*/
public static void countSwaps (List < Integer > a)
{
int count = 0;
boolean flag = false;
while (!flag)
{
flag = true;
for (int i = 0; i < a.size () - 1; i++)
{
if (a.get (i) > a.get (i + 1))
{
int temp = a.get (i);
a.set (i, a.get (i + 1));
a.set (i + 1, temp);
flag = false;
count++;
}
}
}
System.out.println (String.format ("Array is sorted in %d swaps.%n" +
"First Element: %d%n" +
"Last Element: %d%n",
count,
a.get (0), a.get (a.size () - 1)));
}
public static void main (String[]args) throws IOException
{
BufferedReader bufferedReader =
new BufferedReader (new InputStreamReader (System.in));
int n = Integer.parseInt (bufferedReader.readLine ().trim ());
List < Integer > a =
Stream.of (bufferedReader.readLine ().replaceAll ("\\s+$",
"").split (" ")).
map (Integer::parseInt).collect (toList ());
countSwaps (a);
bufferedReader.close ();
}
}
The error: could not find or load main class solution. means your main() method in the Solution class could not be accessed.

SPOJ The next Palindrome ( Java)

import java.util.*;
import java.lang.*;
class Main
{
public static void main (String[] args) throws java.lang.Exception
{
long n,a;
boolean b;
try{
Scanner sc = new Scanner(System.in);
n = sc.nextLong();
for ( long i = 0; i<n; i++){
a = sc.nextLong();
for ( long j = (a+1); j<1000000000; j++){
b = isPalindrome(j);
if ( b == true){
System.out.println(j);
break;
}
}
}
} catch ( Exception e){
return;
}
}
public static boolean isPalindrome(long n){
String intStr = String.valueOf(n);
return intStr.equals(new StringBuilder(intStr).reverse().toString());
}
}
Whats wrong with my Palindrome code?
In SPOJ, the first two test cases are compiling but for the next one and onwards it's showing the wrong answer.
First test case:
2
808
2133
output:
818
2222

The reason is that neither int neither long are big enough to store a given positive integer K of not more than 1000000 digits - 1000000 digits is well 101000000, while Long.MAX_VALUE is only 263-1.
Thus you have to use BigInteger.
The following code seems to work (no more NZEC), but it ends up with time limit exceeded.
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.math.BigInteger;
class Main {
public static void main(String[] args) throws java.lang.Exception {
int n = Integer.parseInt(readLine());
for (int i = 0; i < n; i++) {
BigInteger a = new BigInteger(readLine()).add(BigInteger.ONE);
if (a.signum() == -1) {
a = BigInteger.ZERO;
}
while (a.toString().length() <= 1000000) {
if (isPalindrome(a.toString())) {
System.out.println(a);
break;
}
a = a.add(BigInteger.ONE);
}
}
}
private static boolean isPalindrome(String intStr) {
int l = intStr.length();
for (int i=0, j=l-1; i < l/2+1; i++, j--) {
if (intStr.charAt(i) != intStr.charAt(j)) {
return false;
}
}
return true;
}
private static String readLine() throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
return br.readLine();
}
}

Array index out of bounds

Although I tried to solve the exception using break it still fails on the input "321". Code for bubble sort on hackerrank.
The error occurs on if(a[i+1]==n).
import java.io.*;``
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;
public class Solution {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int n = in.nextInt();
int[] a = new int[n];
for(int a_i=0; a_i < n; a_i++){
a[a_i] = in.nextInt();
}
// Write Your Code Here
int numSwaps=0;
for(int i=0;i<n;i++){
if(a[i+1]==n){ // error occurs here
break;
}
else{
if(a[i]>a[i+1]){
int temp=a[i];
a[i]=a[i+1];
a[i+1]=temp;
numSwaps++;
}
}
}
//firstElement=a[0];
//lastElement=a[n-1];
System.out.println("Array is sorted in"+" "+numSwaps+" "+"swaps."+"\n"+"First Element:"+" "+a[0]+"\n"+"Last Element:"+" "+a[n-1]);
}
}

Your condition i<n will overflow when i=n-1, because you are adding i+1, you are referencing the array out-of-bounds.
The fix is easy, however, change the condition to i<n-1.
import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;
public class Solution {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int n = in.nextInt();
int[] a = new int[n];
for(int a_i=0; a_i < n; a_i++){
a[a_i] = in.nextInt();
}
// Write Your Code Here
int numSwaps=0;
for(int i=0;i<n-1;i++){
if(a[i+1]==n){
break;
} else if(a[i]>a[i+1]){
int temp=a[i];
a[i]=a[i+1];
a[i+1]=temp;
numSwaps++;
}
}
//firstElement=a[0];
//lastElement=a[n-1];
System.out.println("Array is sorted in"+" "+numSwaps+" "+"swaps."+"\n"+"First Element:"+" "+a[0]+"\n"+"Last Element:"+" "+a[n-1]);
}
Also, take bit of pride in code style; I did a couple touch-ups, but its far from clean.

Just change the condition in the for loop to I < n- 1, it occurs due to the I+1 in the swapping module in your Program..

Correct Output for java method

I am trying to create a method that counts the number of times a specified character appears in a given string, by printing the sentence and the specified character and its count.
This is what I have completed so far:-
import java.util.Scanner;
public class Program4 {
public int count ( String sentence, char letter)
{
int times = 0;
for (int x=0;x<sentence.length();x++)
{
if (sentence.charAt(x) ==letter){times++;}
}
return times;
}
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
Program4 program4 = new Program4();
}
program4.count("Hello World",'o');
scan.close();
}
}
I understand I need a "system.output.println" but I don't know what value goes inside to get the output I am looking for. I would appreciate any help, I am beginner with java. Thank you.

it works, you had compile time error in code
import java.util.Scanner;
public class Program4 {
public int count(String sentence, char letter) {
int times = 0;
for (int x = 0; x < sentence.length(); x++) {
if (sentence.charAt(x) == letter) {
times++;
}
}
return times;
}
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
Program4 program4 = new Program4();
int timesCount = program4.count("Hello World", 'o');
System.out.println("count is :" + timesCount);
scan.close();
}
}

Java error method is undefined for the type Echo

I am getting an error on the 11th line of this code "e.results();"
Here is my driver class
import java.util.Scanner;
import java.io.*;
public class LineScrabbleDriver {
public static void main(String args[]) throws IOException {
String fileName;
Scanner nameReader = new Scanner(System.in);
System.out.println("Enter a file name");
fileName = nameReader.nextLine();
Echo e = new Echo(fileName);
e.readLines();
e.results();
}
}
This is the extended class of Echo
import java.io.*;
public class LineScrabble extends Echo{
double max = 0.0;
String bestWord = "";
int lineNumer = 0;
public LineScrabble(String f) throws IOException {
super(f);
}
//scrabbles
int[] scrabbles = {1,3,3,2,1,4,2,4,1,8,5,1,3,1,1,3,10,1,1,1,1,4,4,8,4,10};
//process the given line
public void processLine(String s) {
s.toLowerCase();
int score = 0;
for(int i = 0; i<s.length(); i++){
char ch = s.charAt(i);
if(Character.isLetter(ch)){
int pos = ch - 'a';
score += scrabbles[pos];
}
}
if(score > max){
max = score;
bestWord = s;
}
}
//displays the winner and score
public void results() {
System.out.println("Winner: " + bestWord);
System.out.println("score: " + max/bestWord.length());
}
}
Here is the Echo class
import java.util.Scanner;
import java.io.*;
public class Echo{
String fileName; // external file name
Scanner scan; // Scanner object for reading from external file
public Echo(String f) throws IOException
{
fileName = f;
scan = new Scanner(new FileReader(fileName));
}
public void readLines(){ // reads lines, hands each to processLine
while(scan.hasNext()){
processLine(scan.nextLine());
}
scan.close();
}
public void processLine(String line){ // does the real processing work
System.out.println(line);
}
}
I'm not quite sure why it is giving me a undefined type error. I'm new to java programming. please help!

Because you are using the original Echo and not a LineScrabble, I think you wanted something like -
// Echo e = new Echo(fileName); //
LineScrabble e = new LineScrabble(fileName);
e.readLines();
e.results(); // <-- Echo does not have results() you could add it there, or
// use LineScrabble.