I am stuck at this part right now with adding the groups together. So like, Array1 A + Array2 A
Array1 B + Array 2 B
This is my code:
import java.util.*;
import java.util.Arrays;
public class Math {
public static final int ARRAY1 = 5;
public static final int ARRAY2 = 5;
public static void main(String[] args) {
int de;
de = 1;
System.out.println("Welcome! This program will assist you in\n 1) Adding groups of numbers\n 2) and subtracting a group of numbers\nPlease enter the number of which you need help with!");
Scanner keyboard = new Scanner(System.in);
op = keyboard.nextInt();
if (op == 1) {
System.out.println("****Addition****\nAwesome! Please insert all the numbers for your first group of numbers!");
System.out.println("Enter "+ARRAY1+"");
int[] array = new int[ARRAY1];
for(int i=0;i<array.length;i++)
{
System.out.println("Enter value "+i);
array[i] = keyboard.nextInt();
}
System.out.println("Great! Now please enter your "+ARRAY2+" other group numbers!");
int[] array1 = new int[ARRAY2];
for(int i=0;i<array.length;i++) {
System.out.println("Enter value "+i);
array1[i] = keyboard.nextInt();
}
}
}
}
Initialize the array of the same size and then loop over adding the elements one by one from the 2 input arrays.
int[] sum_array = new int[ARRAY1]; // initialize the output array
for(int i=0;i<array.length;i++) {
sum_array[i] = array[i] + array1[i]; // adding the elements from two arrays
}
for(int i=0;i<array.length;i++) {
System.out.print(sum_array[i] + " ");
}
System.out.println();
The easiest way to solve this is to create another array, let's call it array3, with the same length as your 2 arrays. Then loop over the array3 and store the sum of array1[index] and array2[index] in the array3[index]
Related
I am currently working on a simple program where you're asked "How many random numbers between 0 - 999 do you want?" You enter a value (lets say 3), and it prints "Here are your numbers:" "213 52 821".
How do I go about making the random numbers print in ascending order, from smallest to biggest. I don't want you to write the code for me, just some pointers.
I am really new to programming
import java.util.Scanner;
import java.util.Random;
public class Main {
public static void main(String[] args)
{
Scanner scan = new Scanner(System.in);
System.out.print("How many random numbers between 0 - 999 do you want? ");
int value = scan.nextInt();
System.out.println("Here are your numbers:");
int randomArray[]=new int[value];
for(int i = 0; i<value; i++)
{
randomArray [i] = (int) (Math.random () * 999);
System.out.println(randomArray[i]);
}
}
}
Seems like you have done most of the work. You just need to sort the resulting array.
Use Arrays.sort(randomArray) to sort the array.
Edit: You can print the array outside for-loop with System.out.println(Arrays.toString(randomArray));
Edit 2: In response to your comment, replace the for-loop with this code:
for(int i = 0; i<value; i++)
{
randomArray [i] = (int) (Math.random () * 999);
}
Arrays.sort(randomArray);
System.out.println(Arrays.toString(randomArray));
Edit 3: Replace the for loop in you code with this code if you want both ascending and descending order.
int[] ascendingArray = randomArray.clone();
Arrays.sort(ascendingArray);
int[] descendingArray= ascendingArray.clone();
Collections.reverse(Arrays.asList(descendingArray));
// These two lines print the random array in ascending order.
System.out.println("Sorted array (ascending order):");
System.out.println(Arrays.toString(ascendingArray));
// These two lines print the random array in descending order.
System.out.println("Sorted array (descending order):");
System.out.println(Arrays.toString(descendingArray));
import java.util.Scanner;
import java.util.*;
public class Main {
public static void main(String[] args)
{
Scanner scan = new Scanner(System.in);
System.out.print("How many random numbers between 0 - 999 do you want? ");
int value = scan.nextInt();
System.out.println("Here are your numbers:");
int randomArray[]=new int[value];
for(int i = 0; i<value; i++)
{
randomArray [i] = (int) (Math.random () * 999);
//System.out.println(randomArray[i]);
}
Arrays.sort(randomArray);
System.out.println(randomArray.toString());
}
}
Code written below is correct, but I want to shorten this code.
Write a program in java to enter 10 numbers in Single dimensional array and arrange them in such a way that all even numbers are followed by all odd numbers.
int a[] = new int[6];
int b[] = new int[6];
int i, j;
int k = 0;
System.out.println("enter array");
for (i = 0; i < 6; i++) {
a[i] = sc.nextInt();
}
for (j = 0; j < 6; j++) {
if (a[j] % 2 == 0) {
b[k] = a[j];
k++;
}
}
for (j = 0; j < 6; j++) {
if (a[j] % 2 != 0) {
b[k] = a[j];
k++;
}
}
System.out.println("out-put");
for (i = 0; i < 6; i++) {
System.out.println(b[i]);
}
Can I arrange the even numbers and the odd numbers in a single for loop instead of two for loop? I am using two for loop to transfer the even and the odd numbers into b[] array. Please shorten code. One for loop traverse for checking even number and second for odd numbers.
Here is a simple program for you.
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Scanner;
/**
*
* #author Momir Sarac
*/
public class GroupByEvenAndOddNumbers {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
// create a collection
List<Integer> listOfNumbers = new ArrayList<>();
// do code within a loop for 10 times
for(int i=0;i<10;i++)
{
//print to screen this text
System.out.println("Input your number:");
//get next input integer
int number = scanner.nextInt();
// add it to collection
listOfNumbers.add(number);
}
// sort this collection, list of numbers
// convert all numbers(positive and negative ) within to 0 or 1 depending whether or not they are even or odd and sort them accordignaly.
Collections.sort(listOfNumbers, Comparator.comparingInt(n -> Math.floorMod(n, 2)));
//print sorted collection
System.out.println("Ordered list ..." + listOfNumbers);
}
}
In this version, it copies the even to the start, and the odd to the end.
static int[] sortEvenOdd(int... nums) {
int even = 0, odd = nums.length, ret[] = new int[nums.length];
for (int num : nums)
if (num % 2 == 0)
ret[even++] = num;
else
ret[--odd] = num;
return ret;
}
public static void main(String[] args) {
int[] arr = {1, 3, 2, 4, 7, 6, 9, 10};
int[] sorted = sortEvenOdd(arr);
System.out.println(Arrays.toString(sorted));
}
prints
[2, 4, 6, 10, 9, 7, 3, 1]
This Code will help you to segregate Even and Odd numbers.
// java code to segregate even odd
// numbers in an array
public class GFG {
// Function to segregate even
// odd numbers
static void arrayEvenAndOdd(
int arr[], int n)
{
int i = -1, j = 0;
while (j != n) {
if (arr[j] % 2 == 0)
{
i++;
// Swapping even and
// odd numbers
int temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
}
j++;
}
// Printing segregated array
for (int k = 0; k < n; k++)
System.out.print(arr[k] + " ");
}
// Driver code
public static void main(String args[])
{
int arr[] = { 1, 3, 2, 4, 7,
6, 9, 10 };
int n = arr.length;
arrayEvenAndOdd(arr, n);
}
}
As you don't have any requirements that the even and odd numbers itself have to be ordered in their respectively half of the array you can just assign them to their associated array part while entering them.
Therefore you just have to use two "counter" variables one for the left which starts at zero and is incremented and one for the right which starts at your array length minus one and is decremented. Then you can add your numbers, checking if one is even add assign it with your left counter post incremented and if one is odd assign it with your right counter post decremented. Do this within a loop, until your left counter is bigger than your right counter.
I created a simple example where I did not check for NumberFormatException when parsing the String to an int:
import java.util.Arrays;
import java.util.Scanner;
public class SortedArrayInput {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.print("Enter length of array: ");
final int arrayLength = Integer.parseInt(scanner.nextLine());
int intArray[] = new int[arrayLength];
for (int l = 0, r = arrayLength - 1; l <= r; ) {
System.out.print("Enter new array value: ");
int v = Integer.parseInt(scanner.nextLine());
intArray[v % 2 == 0 ? l++ : r--] = v;
}
System.out.println("Output: " + Arrays.toString(intArray));
}
}
Sample input/output:
Enter length of array: 6
Enter new array value: 1
Enter new array value: 2
Enter new array value: 3
Enter new array value: 4
Enter new array value: 5
Enter new array value: 6
Output: [2, 4, 6, 5, 3, 1]
I recommend reading up on streams, they will make collection processing a lot easier for you
List<Integer> numbers = new ArrayList<>();
numbers.add(1);
numbers.add(2);
numbers.add(3);
numbers.add(4);
numbers.add(5);
numbers.add(6);
numbers.add(7);
numbers.add(8);
numbers.add(9);
numbers.add(0);
//this way you simply traverse the numbers twice and output the needed ones
System.out.println(numbers.stream()
.filter(x->x%2==0)
.collect(Collectors.toList()));
System.out.println(numbers.stream()
.filter(x->x%2==1)
.collect(Collectors.toList()));
//this way you can have the numbers in two collections
numbers.forEach(x-> x%2==0? addItToEvenCollection : addItToOddCollection);
//this way you will have a map at the end. The boolean will tell you if the numbers are odd or even,
// and the list contains the numbers, in order of apparition in the initial list
numbers.stream().collect(Collectors.groupingBy(x->x%2==0));
A performant way to check if a number is even, is to use
if ( (x & 1) == 0 )
Code written below is correct, but I want to shorten this code.
Write a program in java to enter 10 numbers in Single dimensional array and arrange them in such a way that all even numbers are followed by all odd numbers.
int a[] = new int[6];
int b[] = new int[6];
int i, j;
int k = 0;
System.out.println("enter array");
for (i = 0; i < 6; i++) {
a[i] = sc.nextInt();
}
for (j = 0; j < 6; j++) {
if (a[j] % 2 == 0) {
b[k] = a[j];
k++;
}
}
for (j = 0; j < 6; j++) {
if (a[j] % 2 != 0) {
b[k] = a[j];
k++;
}
}
System.out.println("out-put");
for (i = 0; i < 6; i++) {
System.out.println(b[i]);
}
Can I arrange the even numbers and the odd numbers in a single for loop instead of two for loop? I am using two for loop to transfer the even and the odd numbers into b[] array. Please shorten code. One for loop traverse for checking even number and second for odd numbers.
Here is a simple program for you.
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Scanner;
/**
*
* #author Momir Sarac
*/
public class GroupByEvenAndOddNumbers {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
// create a collection
List<Integer> listOfNumbers = new ArrayList<>();
// do code within a loop for 10 times
for(int i=0;i<10;i++)
{
//print to screen this text
System.out.println("Input your number:");
//get next input integer
int number = scanner.nextInt();
// add it to collection
listOfNumbers.add(number);
}
// sort this collection, list of numbers
// convert all numbers(positive and negative ) within to 0 or 1 depending whether or not they are even or odd and sort them accordignaly.
Collections.sort(listOfNumbers, Comparator.comparingInt(n -> Math.floorMod(n, 2)));
//print sorted collection
System.out.println("Ordered list ..." + listOfNumbers);
}
}
In this version, it copies the even to the start, and the odd to the end.
static int[] sortEvenOdd(int... nums) {
int even = 0, odd = nums.length, ret[] = new int[nums.length];
for (int num : nums)
if (num % 2 == 0)
ret[even++] = num;
else
ret[--odd] = num;
return ret;
}
public static void main(String[] args) {
int[] arr = {1, 3, 2, 4, 7, 6, 9, 10};
int[] sorted = sortEvenOdd(arr);
System.out.println(Arrays.toString(sorted));
}
prints
[2, 4, 6, 10, 9, 7, 3, 1]
This Code will help you to segregate Even and Odd numbers.
// java code to segregate even odd
// numbers in an array
public class GFG {
// Function to segregate even
// odd numbers
static void arrayEvenAndOdd(
int arr[], int n)
{
int i = -1, j = 0;
while (j != n) {
if (arr[j] % 2 == 0)
{
i++;
// Swapping even and
// odd numbers
int temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
}
j++;
}
// Printing segregated array
for (int k = 0; k < n; k++)
System.out.print(arr[k] + " ");
}
// Driver code
public static void main(String args[])
{
int arr[] = { 1, 3, 2, 4, 7,
6, 9, 10 };
int n = arr.length;
arrayEvenAndOdd(arr, n);
}
}
As you don't have any requirements that the even and odd numbers itself have to be ordered in their respectively half of the array you can just assign them to their associated array part while entering them.
Therefore you just have to use two "counter" variables one for the left which starts at zero and is incremented and one for the right which starts at your array length minus one and is decremented. Then you can add your numbers, checking if one is even add assign it with your left counter post incremented and if one is odd assign it with your right counter post decremented. Do this within a loop, until your left counter is bigger than your right counter.
I created a simple example where I did not check for NumberFormatException when parsing the String to an int:
import java.util.Arrays;
import java.util.Scanner;
public class SortedArrayInput {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.print("Enter length of array: ");
final int arrayLength = Integer.parseInt(scanner.nextLine());
int intArray[] = new int[arrayLength];
for (int l = 0, r = arrayLength - 1; l <= r; ) {
System.out.print("Enter new array value: ");
int v = Integer.parseInt(scanner.nextLine());
intArray[v % 2 == 0 ? l++ : r--] = v;
}
System.out.println("Output: " + Arrays.toString(intArray));
}
}
Sample input/output:
Enter length of array: 6
Enter new array value: 1
Enter new array value: 2
Enter new array value: 3
Enter new array value: 4
Enter new array value: 5
Enter new array value: 6
Output: [2, 4, 6, 5, 3, 1]
I recommend reading up on streams, they will make collection processing a lot easier for you
List<Integer> numbers = new ArrayList<>();
numbers.add(1);
numbers.add(2);
numbers.add(3);
numbers.add(4);
numbers.add(5);
numbers.add(6);
numbers.add(7);
numbers.add(8);
numbers.add(9);
numbers.add(0);
//this way you simply traverse the numbers twice and output the needed ones
System.out.println(numbers.stream()
.filter(x->x%2==0)
.collect(Collectors.toList()));
System.out.println(numbers.stream()
.filter(x->x%2==1)
.collect(Collectors.toList()));
//this way you can have the numbers in two collections
numbers.forEach(x-> x%2==0? addItToEvenCollection : addItToOddCollection);
//this way you will have a map at the end. The boolean will tell you if the numbers are odd or even,
// and the list contains the numbers, in order of apparition in the initial list
numbers.stream().collect(Collectors.groupingBy(x->x%2==0));
A performant way to check if a number is even, is to use
if ( (x & 1) == 0 )
I have to create a program that reads an arbitrary number of positive integers from the user and store them into an array. The number of input data is not more than 100. After the user finishes the program should remove all even integers and place them in another array leaving all odd integers in the original array with no holes. It should display the contents in the original array as the order of input, the contents of the even integer array with a count, and the contents of the original array after taking out all even integers with a count
No third array should be used
Im having trouble displaying the original array and original integer array after taking out the even integers. here is my code so far
import java.util.*;
public class Arrays
{
public static void main(String[] args)
{
Scanner scan = new Scanner(System.in);
System.out.println("Enter in any amount of positive numbers, Enter -1 when finished");
int i=0;
int nextElm=0;
int a,b;
int[] origArray = new int[100]; /* Two arrays at length 100*/
int[] evenArray = new int[100];
while((i<origArray.length && i<evenArray.length)&& nextElm!= -1)
{
System.out.println("Enter next number: ");
nextElm = scan.nextInt();
if (nextElm%2 != 0)//Sorts even numbers
{
origArray[i]= nextElm;
}
else
evenArray[i] = nextElm;
i++;
}
System.out.print("\n");
System.out.println("Even Array: ");
for (b=0; b<evenArray.length;b++)
{
if (evenArray[b]== -1)
{
evenArray[b]= 0;
}
if(evenArray[b]!= 0)
{
System.out.print(evenArray[b]+" ");
}
}
System.out.print("\n");
System.out.println("Original Array: ");
for(a=0; a<origArray.length && a<evenArray.length; a++)
{
if (origArray[a]== -1)
{
origArray[a]= 0;
}
if(origArray[a]!= 0)
{
System.out.print(origArray[a]+" " + evenArray[a]);
}
}
System.out.print("\n");
}
}
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println("Enter in any amount of positive numbers, Enter -1 when finished");
int i = 0;
int nextElm = 0;
int a, b;
int[] origArray = new int[100]; /* Two arrays at length 100 */
int[] evenArray = new int[100];
while (nextElm != -1) {
System.out.println("Enter next number: ");
nextElm = scan.nextInt();
if (nextElm > 0) {
origArray[i] = nextElm;
i++;
}
}
int x = 0;
System.out.println();
// Displays original array and sorts even numbers to even array +
// original count
System.out.printf("\nTotal count of original array is : %d", i);
System.out.println();
for (int orgNumber : origArray) {
if (orgNumber != 0) {
System.out.print(orgNumber + " ");
}
if (orgNumber % 2 == 0) {
if (orgNumber != 0) {
evenArray[x] = orgNumber;
x++;
}
}
}
System.out.println();
// Displays sort even numbers to even array + even count
System.out.printf("\nTotal count of even array is : %d", x);
System.out.println();
for (int evenNumber : evenArray) {
if (evenNumber != 0) {
System.out.print(evenNumber + " ");
}
}
// Displays sort odd numbers from original array + odd count
System.out.printf("\nTotal count of orignal array without even is : %d", i - x);
System.out.println();
for (int oddNumber : origArray) {
if (oddNumber % 2 != 0) {
System.out.print(oddNumber + " ");
}
}
}
This should work perfectly if I understood your question well. Hope you find this helpful.
You want three separate loops. One for inputting the values (I would suggest the while construct as you have done) and one for sorting the values.
Your input loop should read in a new number each time and only quit when the user wants to. For example, if the user inputs a negative number, then your loop will quit. Like this:
System.out.println("Enter any number of numbers; enter a negative when finished.");
int nextElm = 0;
int count = 0;
while (nextElm >= 0) {
nextElm = scan.nextInt();
origArray[count] = nextElm;
count++;
}
// This is where you would put a print statement that prints the original array with a count.
Now after this, use the java.util.Arrays.copyOf() method to trim out the empty elements of the array, like so:
origArray = java.util.Arrays.copyOf(origArray, count+1);
Next, use a for loop to iterate through the array, and move even numbers to the other array. This is the tricky part, because removing items from an array requires iteration to move each value to it's previous index.
int j = 0;
for (int i=0; i<count; i++){
if (origArray[i] % 2 == 0){
evenArray[j] = origArray[i]; //add even number to evenArray
j++; //move to next index of evenArray
for (int k=i; k<(origArray.length-1); k++){
origArray[k] = origArray[k+1]; //store next value in current index
}
}
}
Then finally, use the java.util.Arrays.copyOf() method to trim out the empty elements of the array again, like so:
evenArray = java.util.Arrays.copyOf(evenArray, j+1);
Disclaimer: This was all coded from the hip so let me know if I missed something or did something incorrectly.
I'm asking the user to enter some numbers between 1 and 100 and assign them into an array. The array size is not initialized since it is dependent on the number of times the user enters a number.
How should I assign the array length?
If user enters 5 6 7 8 9 (5 numbers), then
int[] list;
becomes
int[] list = new int[5];
I'm trying to use a loop, but it won't stop.
int[] integers;
int j = 0;
do {
integers = new int[j + 1];
integers[j] = in.nextInt();
j++;
} while((integers[j-1] >= 1) ||(integers[j-1]) <= 100);
You should use a List for something like this, not an array. As a general rule of thumb, when you don't know how many elements you will add to an array before hand, use a List instead. Most would probably tackle this problem by using an ArrayList.
If you really can't use a List, then you'll probably have to use an array of some initial size (maybe 10?) and keep track of your array capacity versus how many elements you're adding, and copy the elements to a new, larger array if you run out of room (this is essentially what ArrayList does internally). Also note that, in the real world, you would never do it this way - you would use one of the standard classes that are made specifically for cases like this, such as ArrayList.
I think you need use List or classes based on that.
For instance,
ArrayList<Integer> integers = new ArrayList<Integer>();
int j;
do{
integers.add(int.nextInt());
j++;
}while( (integers.get(j-1) >= 1) || (integers.get(j-1) <= 100) );
You could read this article for getting more information about how to use that.
I agree that a data structure like a List is the best way to go:
List<Integer> values = new ArrayList<Integer>();
Scanner in = new Scanner(System.in);
int value;
int numValues = 0;
do {
value = in.nextInt();
values.add(value);
} while (value >= 1) && (value <= 100);
Or you can just allocate an array of a max size and load values into it:
int maxValues = 100;
int [] values = new int[maxValues];
Scanner in = new Scanner(System.in);
int value;
int numValues = 0;
do {
value = in.nextInt();
values[numValues++] = value;
} while (value >= 1) && (value <= 100) && (numValues < maxValues);
If you want to stick to an array then this way you can make use. But its not good as compared to List and not recommended. However it will solve your problem.
import java.util.Scanner;
public class ArrayModify {
public static void main(String[] args) {
int[] list;
String st;
String[] stNew;
Scanner scan = new Scanner(System.in);
System.out.println("Enter Numbers: "); // If user enters 5 6 7 8 9
st = scan.nextLine();
stNew = st.split("\\s+");
list = new int[stNew.length]; // Sets array size to 5
for (int i = 0; i < stNew.length; i++){
list[i] = Integer.parseInt(stNew[i]);
System.out.println("You Enterred: " + list[i]);
}
}
}
String line=sc.nextLine();
int counter=1;
for(int i=0;i<line.length();i++) {
if(line.charAt(i)==' ') {
counter++;
}
}
long[] numbers=new long[counter];
counter=0;
for(int i=0;i<line.length();i++){
int j=i;
while(true) {
if(j>=line.length() || line.charAt(j)==' ') {
break;
}
j++;
}
numbers[counter]=Integer.parseInt(line.substring(i,j));
i=j;
counter++;
}
for(int i=0;i<counter;i++) {
System.out.println(numbers[i]);
}
I always use this code for situations like this. beside you can recognize two or three or more digit numbers.
int i,largest = 0;
Scanner scan = new Scanner(System.in);
System.out.println("Enter the number of numbers in the list");
i = scan.nextInt();
int arr[] = new int[i];
System.out.println("Enter the list of numbers:");
for(int j=0;j<i;j++){
arr[j] = scan.nextInt();
}
The above code works well. I have taken the input of the number of elements in the list and initialized the array accordingly.
**input of list of number for array from single line.
String input = sc.nextLine();
String arr[] = input.split(" ");
int new_arr[] = new int[arr.length];
for(int i=0; i<arr.length; i++)
{
new_arr[i] = Integer.parseInt(arr[i]);
}