Write a Java program that separates the even and odd numbers in an integer array

Question

I need to write a java program that seperates he even and odd numbers in an integer array.

This is what I have so far: This part is perfect:

package Homework;
import java.util.*;
public class EvenOdd
{
public static void main(String[] args)
{
    // TODO Auto-generated method stub
    System.out.println("Please enter 10 integers");
    int [] a= new int[10];
    Scanner sc = new Scanner(System.in);
    for(int i=0;i<a.length;i++)
    {
        System.out.print("The "+(i+1)+" integer = ");
        a[i]= sc.nextInt();
    }     

        System.out.println("\nThe resulting array");
        for(int i=0;i<a.length;i++)
        {
            for(int j=1;j<a.length;j++)
            {
                int temp;
                if(a[i]%2!=0 && a[j]%2==0 && j>i)
                {
                    temp=a[j];
                    a[j]=a[i];
                    a[j]=temp;
                    break;     //There seems to be some problem in this loop
                }
            }
            System.out.println("The "+(i+1)+" integer = "+a[i]);
        }

Answer 1

If you use %2 which is modulo, you should be able to find if numbers are even or odd as even numbers mod 2 will equal 0 and odd numbers mod 2 will equal 1.

Try this for sorting the array:

    for(int i=0;i<count;i++)
    {
        if(a[i] %2 != 0){//even
            int temp = a[i];
            a[i--] = a[count--];
            a[count+1] = temp;
        }
    }

Answer 2

Introduce two Integer type ArrayLists list1 and list2. Put even numbers into list1 and odd numbers into list2. Merge both into list1.

public class EvenOdd {

    public static void main(String[] args) {

        System.out.println("Please enter 10 integers");
        int[] a = new int[10];
        ArrayList<Integer> list1 = new ArrayList();
        ArrayList<Integer> list2 = new ArrayList();
        Scanner sc = new Scanner(System.in);
        for (int i = 0; i < a.length; i++) {
            System.out.print("The " + (i + 1) + " integer = ");
            a[i] = sc.nextInt();
            if (a[i] % 2 == 0) {
                list1.add(a[i]);
            } else {
                list2.add(a[i]);
            }
        }
        list1.addAll(list2);
        for (int b : list1) {
            System.out.print(b + " ");
        }

    }
}

Answer 3

import java.util.*;
class main11
{
    public static void main(String args[])
    {
        Scanner sc=new Scanner(System.in);
        System.out.println("Enter the range");
        int no=sc.nextInt();
        int a[]=new int[no];
        int i;
        System.out.println("Enter the elements");
        for(i=0;i<no;i++)
        {
            a[i]=sc.nextInt();
        }
        System.out.println("Even nos are");
        for(i=0;i<no;i++)
        {
            if(a[i]%2==0)
            { 
                System.out.println(a[i]);

            }

        }
        System.out.println("The odd nos are");
        for(i=0;i<no;i++)
        {
            if(a[i]%2!=0)
            { 
                System.out.println(a[i]);

            }

        }




        }

    }   

Answer 4

I believe your swapping of elements is not working due to a typo:

temp=a[j];
a[j]=a[i];
a[i]=temp;   //Should be a[i] and not a[j]
break;

Also you can reduce the number of iterations by making the following changes in your for loops:

for(int i=0;i<a.length-1;i++)
{
     for(int j=i+1;j<a.length;j++)
     {
          int temp;
          if(a[i]%2!=0 && a[j]%2==0) //no need of the last condition

Answer 5

//To store even and odd element in 2 diifferent array Aand print it//
import java.util.*;
class main11
{
    public static void main(String args[])
    {
        Scanner sc=new Scanner(System.in);
        System.out.println("Enter the range");
        int no=sc.nextInt();
        int a[]=new int[no];
        int i,j=0,k=0;
        System.out.println("Enter the elements");
        for(i=0;i<no;i++)
        {
            a[i]=sc.nextInt();
        }
        int even[]=new int[no];
        int odd[]=new int[no];
        System.out.println("Even nos are");
        for(i=0;i<no;i++)
        {
            if(a[i]%2==0)
            { 
                even[i]=a[i];//to store element in even array//
                System.out.println(even[i]+" ");

            }

        }
        System.out.println("The odd nos are");
        for(i=0;i<no;i++)
        {
            if(a[i]%2!=0)
            {  
                odd[i]=a[i];//to store element in odd array//

                System.out.println(odd[i]+" ");

            }

        }




        }

    }   

Answer 6

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        int j=0,k=0,n;
        Scanner scn = new Scanner(System.in);
        System.out.println("Enter number of element you want in your array:");
         n = scn.nextInt();
        int array[] = new int[n];
        System.out.println("Your array element is : ");
        for (int i=0;i<n;i++){
            array[i]= scn.nextInt();
        }

        int even[] = new int[n];
        int odd[] = new int[n];
        for (int i=0;i<n;i++){
            if (array[i] % 2 != 0){
                odd[j] = array[i];
                j++;
            }
            else{
                even[k] = array[i];
                k++;
            }
        }

        System.out.println("Odd Array");
        if (j>1)
        {
            for (int i=0;i<j-1;i++){
                System.out.println(odd[i]+",");
            }
            System.out.println(odd[j-1]);

        }
        else {
            System.out.println("No number");
        }
        System.out.println(" ");
        System.out.print("Even :");
        System.out.println("Odd Array");
        if (k>1)
        {
            for (int i=0;i<k-1;i++){
                System.out.println(even[i]+",");
            }
            System.out.println(even[k-1]);

        }
        else {
            System.out.println("No number");
        }


    }
}