Please tell me why I can't get output here?

Question about the task

Longest sequence

Java Syntax, Level 8, Lesson 6

Resolved

1. Create a list of numbers.
2. Use the keyboard to add 10 numbers to the list.
3. Display the length of the longest sequence of repeating numbers in the list.

Example for the list 2, 4, 4, 4, 8, 8, 4, 12, 12, 14:
3

The value is 3, because the longest sequence of repeating numbers is three fours.

Requirements:

The program must display a number on the screen.
The program should read values from the keyboard.
In the main method, declare an ArrayList variable with Integer elements and immediately initialize it.
The program should add 10 numbers to the collection in accordance with the conditions.
The program should display the length of the longest sequence of repeating numbers in the list.

package com.codegym.task.task08.task0812; import java.io.*; import java.util.ArrayList; /* Longest sequence */ public class Solution { public static void main(String[] args) throws IOException { //write your code here BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); ArrayList<Integer> list = new ArrayList<Integer>(); ArrayList<Integer> countList = new ArrayList<Integer>(); for (int i = 0; i < 10; i++){ int s = Integer.parseInt(reader.readLine()); list.add(i, s); } int count = 1; int maxCount = 1; for (int i = 0; i < list.size(); i++){ if (list.get(i) == list.get(i + 1)){ count ++; } else { countList.add(count); count = 1; } } for (int i = 0; i < countList.size(); i++){ if (countList.get(i) >= maxCount){ maxCount = count; } } System.out.println(maxCount); } }

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Ewerton Backend Developer

12 July 2019, 15:54

solution

for (int i = 0; i < list.size(); i++){
     if (list.get(i) == list.get(i + 1)){

Your list goes from 0 to 9.

list.size() = 10

So when i=9, you are trying to access list at index 10.

Yuchen

Level 17 , Los Angeles, America

14 July 2019, 12:18

Thank you for your help. I changed the way to count loop and fix some minor problems, but I still can't pass the test. Could you please tell me what is wrong with it?

package com.codegym.task.task08.task0812;

import java.io.*;
import java.util.ArrayList;

/*
Longest sequence

*/
public class Solution {
    public static void main(String[] args) throws IOException {
        //write your code here
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        ArrayList<Integer> list = new ArrayList<Integer>();
        ArrayList<Integer> countList = new ArrayList<Integer>();

        for (int i = 0; i < 10; i++){
            int s = Integer.parseInt(reader.readLine());
            list.add(s);
        }

        int count = 1;
        int maxCount = 1;

        for (int i = 9; i > 0; i--){
            if (list.get(i).equals(list.get(i - 1))){
                count ++;
            } else {
                countList.add(count);
                count = 1;
            }

        }

        for (int i = 0; i < countList.size(); i++){
            if (countList.get(i) >= maxCount){
                maxCount = countList.get(i);
            }
        }

        System.out.println(maxCount);

    }
}