Hi, don't know what I've done wrong here.

Question about the task

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Hello everyone, I don't know how to get the last two conditions correct. Can somebody help me, please?

1. Enter 20 numbers from the keyboard, save them in a list, and then sort them to three other lists:
Numbers divisible by 3 (x%3==0), numbers divisible by 2 (x%2==0), and all other numbers.
Numbers simultaneously divisible by 3 and 2 (for example 6) go into both lists.
The order in which the lists are declared is very important.
2. The printList method should display each list item on a new line.
3. Using the printList method, display these three lists. First, the list for x%3, then the list for x%2, and then the last list.

Requirements:

Declare and immediately initialize 4 ArrayList<Integer> variables. The first list will be the main one. The other lists will be supplementary.
Read 20 numbers from the keyboard and add them to the main list.
Add to the first supplementary list all numbers in the main list that are divisible by 3.
Add to the second supplementary list all numbers in the main list that are divisible by 2.
Add to the third supplementary list all the remaining numbers from the main list.
The printList method should display each element of the passed list on a new line.
The program should display the three supplementary lists using the printList method.

package com.codegym.task.task07.task0713; import java.io.BufferedReader; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.List; /* Playing Javarella */ public class Solution { public static void main(String[] args) throws Exception { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); ArrayList<Integer> mainList = new ArrayList<Integer>(); ArrayList<Integer> div3List = new ArrayList<Integer>(); ArrayList<Integer> div2List = new ArrayList<Integer>(); ArrayList<Integer> restList = new ArrayList<Integer>(); for (int i = 0; i<20; i++){ int x = Integer.parseInt(reader.readLine()); if (x % 3 == 0){ div3List.add(x);} else if (x % 2 == 0){ div2List.add(x);} else{ restList.add(x); } } printList(div3List); printList(div2List); printList(restList); } public static void printList(List<Integer> list) { for (int i = 0; i<div3List.size(); i++){ System.out.println(div3List.get(i)); } for (int i = 0; i<div2List.size(); i++){ System.out.println(div2List.get(i)); } for (int i=0; i<restList.size(); i++){ System.out.println(restList.get(i)); }//write your code here } }

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Molchyn

Level 25 , Yahil'nytsya, Ukraine

4 May 2019, 09:22

public class Solution { public static void main(String[] args) throws Exception { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); ArrayList<Integer> mainList = new ArrayList<Integer>(); ArrayList<Integer> div3List = new ArrayList<Integer>(); ArrayList<Integer> div2List = new ArrayList<Integer>(); ArrayList<Integer> restList = new ArrayList<Integer>(); for (int i = 0; i < 20; i++){ int x = Integer.parseInt(reader.readLine()); if (x % 3 == 0){ div3List.add(x);} if (x % 2 == 0){//4.Add to the second supplementary list all numbers in the main list that are divisible by 2. div2List.add(x);} /*else{ restList.add(x); }*/ if (!(mainList.get(i) % 3 == 0) && !(mainList.get(i) % 2 == 0)) restList.add(list.get(i));//5.Add to the third supplementary list all the remaining numbers from the main list. } printList(div3List); printList(div2List); printList(restList); } public static void printList(List<Integer> list) { //We still have one more requirement 6.The printList method should display each element of the passed list on a new line. for (int i = 0; i < list.size(); i++) { System.out.println(list.get(i)); } /*for (int i = 0; i<div3List.size(); i++){ System.out.println(div3List.get(i)); } for (int i = 0; i<div2List.size(); i++){ System.out.println(div2List.get(i)); } for (int i=0; i<restList.size(); i++){ System.out.println(restList.get(i)); }//write your code here*/ } } That's so short for your code

somecro

Level 15 , Zagreb, Croatia

28 April 2019, 17:59

The first thing I notice is this statement: "Numbers simultaneously divisible by 3 and 2 (for example 6) go into both lists." Looking at your code, if we enter number 6 the first IF statement will return true and the number will only get written to the DIVISBLE BY 3 list and it will not get entered into the DIVISIBLE BY 2 list. Also the printList() method is wrong. Look at the parameter that the method accepts, and then look at your FOR loops. You only need one FOR loop with the correct variable (parameter in this case).