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can someone help me to print this pattern in java or help me with the logic

5
54
543
5432
54321
I tried to print the pattern above using the following for loop but I don't know why it's not working,
for(int i = 0;i<=5;i++,count = 1,System.out.println()){
for(int j = 5;j>=i;j--)
{
System.out.print("");
}
for (int k = 5;count <=i;count++,k--)
{
System.out.print(k+"");
}

You need something like this:
for (int i = 0; i < 5; i++) {
int count = 0;
for (int j = 5; j >= i; j--) {
System.out.print(" ");
}
for (int k = 5; count <= i; count++, k--) {
System.out.print(k);
}
System.out.println();
}
It prints:
5
54
543
5432
54321
Your mistakes:
At for(int i = 0;i<=5;i++,count = 1,System.out.println()){
This is not a good place for: count = 1,System.out.println()
At System.out.print(""); This doesn't print anything.
At System.out.print(k+""); the +"" is not necessary.

Assuming you need to print pattern for string "54321" only:
public class Answer {
public static void main(String[] args) {
String line = "54321";
for (int i = 1; i <= 5; i++) {
System.out.format("%5s%n", line.substring(0, i));
}
}
}
However you can print any line with this triangular pattern:
public class Answer {
public static void main(String[] args) {
String alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
printTriangle(alphabet);
String digits = "9876543210";
printTriangle(digits);
}
private static void printTriangle(String line) {
int lineLen = line.length();
for (int i = 1; i <= lineLen; i++) {
System.out.format("%" + lineLen + "s%n", line.substring(0, i));
}
}
}

How to break a one-dimensional array in rows?

I want to break a one-dimensional array in rows.
Array dimension 50. I need to output the array to the console with 10 elements per line. (lang Java 1.8) Thanks!
public void print() {
for (int i = 0; i < arr.length; i++) {
if (i<=9) {
System.out.print(arr[i] + " ");
}else {
System.out.print("\r");
}
}
}
Sample output
0 1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16
etc....

You can see it from 2 differents point of view
Each 10 numbers, print a new line : when the index ends with a 9 you reach ten elements so you print a new line println()
public void print() {
for (int i = 0; i < arr.length; i++) {
System.out.print(arr[i] + " ");
if (i % 10 == 9) {
System.out.println();
}
}
}
Print enough number of line and on each one : print 10 elements
public void print() {
for (int i = 0; i < arr.length / 10; i++) {
for (int j = 0; j < 10; j++) {
System.out.print(arr[i * 10 + j] + " ");
}
System.out.println();
}
}

Code for any number of elements per line:
public void print(int elementsPerLine) {
for (int i = 0; i < arr.length; i++) {
System.out.print(arr[i]);
if (i % elementsPerLine == 0 && i > 0) {
System.out.println();
} else {
System.out.print(" ");
}
}
}

Use the following code,
public static void printResult(int[][] result)
{
for(int i=0; i<5; i++)
{
for(int j=0; j<10; j++)
{
System.out.print(result[i][j] + ", ");
}
System.out.println();
}
}
public static int[][] modifyArray( int[] singleArray )
{
int columns = 10;
int rows = singleArray.length/10;
int[][] result = new int[rows][columns];
for(int i=0; i<rows; i++)
{
for(int j=0; j<columns; j++)
{
result[i][j] = singleArray[columns*i + j];
}
}
return result;
}
public static void main(String[] args)
{
int[] singleArray = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50};
int[][] result = modifyArray( singleArray);
printResult( result );
}

You must use the modulo operator
https://en.wikipedia.org/wiki/Modulo_operation
public void print() {
for (int i = 0; i < arr.length; i++) {
if (i%10 == 0) {
System.out.print("\r");
}else {
System.out.print(arr[i] + " ");
}
}
}

Maybe you could write something like
if (i % 10 == 0)
System.out.print("\r");
}
System.out.print(arr[i] + " ");

Take slices of 10 items into a new array each time and print that array:
int count = 10;
int iterations = (arr.length / count) + ((arr.length % count) > 0 ? 1 : 0);
for (int i = 1; i <= iterations; i++) {
int[] slice = new int[count];
System.arraycopy(arr, (i - 1) * count, slice, 0, i == iterations ? (array.length % count) : count);
System.out.println(Arrays.toString(slice));
}
The above code works for any value of count.

Take a look at a code down below:
public class PrintEach10thElements {
/**
* #param args the command line arguments
*/
static List<Integer> arrays = new ArrayList<>();
public static void main(String[] args) {
//create 50 elements in an array
for (int i = 0; i <= 49; i++) {
arrays.add(i);
}
for (int g = 0; g < arrays.size(); g++) {
if ( arrays.get(g) % 10 != 0) {
System.out.print(arrays.get(g) + " ");
} else {
System.out.println();
System.out.print(arrays.get(g) + " ");
}
}
}
}

If you don't mind using a Guava library, you can also do this
List<Integer> myList = Arrays.asList(myArray);
System.out.println(Lists.partition(myList, 10).stream()
.map(subList -> subList.stream()
.map( Object::toString )
.collect(Collectors.joining(" ")))
.collect(Collectors.joining("\n")));

How can I alter this code so that the output is flipped?

I am making this code that displays a series of asterisks in rows that get smaller by one each time you go down a row. It's supposed to start at 10 and stop at 1 on the very bottom row but for some reason my code starts with 1 at the top and grows bigger as it goes down. I was wondering how I could go about flipping the output so that it looks like the example. Thanks in advance
Example:
**********
*********
********
*******
******
*****
****
***
**
*
My code:
public class RowsOfAsterisks {
public static void main(String[] args) {
// TODO Auto-generated method stub
for (int i = 1; i < 11; i++)
{
for (int x = 0; x < i; x++)
{
System.out.print("*");
}
System.out.println();
}
}
}

You can create another method in order to avoid two for statment
Check if it can help you:
public class RowsOfAsterisks
{
public static String repeat(String str, int times)
{
return new String(new char[times]).replace("\0", str);
}
public static void main(String[] args)
{
for(int i = 10; i > 0; i--)
{
System.out.println(repeat("*", i));
}
}
}

You just have to start the outer loop from 10 to achieve this.
I hope the below code helps you:
public class RowsOfAsterisks {
public static void main(String[] args) {
for (int i = 10; i > 0; i--)
{
for (int x = 0; x < i; x++)
{
System.out.print("*");
}
System.out.println();
}
}
}

int rows = 10;
int columns = 10;
for(int i = 0; i<rows; i++)
{
for(int j = 0; int j < columns; j++)
{
System.out.print("*");
}
System.out.println();
--columns;
}

You're on the right track you just need to fix up the nested loop like so:
public static void main(String[] args) {
for (int i = 1; i < 11; i++)
{
for (int x = 11; x > i; x--)
{
System.out.print("*");
}
System.out.println();
}
}

How to print specified pattern in Java

I want to print the below pattern
v
v v
v v
v v
Below is the code which I have tried.
public static void main(String[] args) {
System.out.println("The Pattern is");
for (int i = 0; i < 4; i++) {
//System.out.println(i);
for (int k = 0; k <= i - 2; k++) {
System.out.print("v ");
}
for (int j = 0; j <= 4 - i; j++) {
System.out.print(" ");
}
System.out.println();
}
}
I'm getting the below output:
v
v v
Can anyone help me to solve this pattern?

Another way to do the job (dynamic number of rows):
public static void main(String[] args) {
final int numRows = 4;
for (int row = 0; row < numRows; row++) {
for (int preSpace = numRows - row; preSpace >= 0; preSpace--) {
System.out.print(" ");
}
if (row > 0) {
System.out.print("v");
for (int postSpace = 1; postSpace < row * 2; postSpace++) {
System.out.print(" ");
}
}
System.out.println("v");
}
}

Move the j loop before k loop
public static void main (String[] args) throws java.lang.Exception
{
System.out.println("The Pattern is");
for(int i=0;i<4;i++) {
for(int j=0;j<=4-i;j++)
System.out.print(" ");
for(int k=0;k<=i-2;k++)
System.out.print("V ");
System.out.println();
}
}
DEMO

The following code will print it
public static void main(String[] args) {
System.out.println("The Pattern is");
// startup parameter
final int rowSize = 4;
final int startPos = 2;
int leftPos = startPos;
int rightPos = startPos;
// for each row
for(int row=0; row<rowSize; row++){
// find and print v (max is right most v)
for(int col=0; col<rightPos+1; col++){
// when reach left pos
if(col==leftPos){
System.out.print("v");
// when left pos and right pos is same
if(leftPos==rightPos){
break;
}
}
// when reach right pos
if (col==rightPos){
System.out.print("v");
break;
}
// print space when it is not match
System.out.print(" ");
}
// next line
System.out.println();
// adjust position
if(leftPos!=0) leftPos--;
rightPos++;
}
}

This works for me:
public class DrawPattern {
public static void main(String[] args) {
int i, j;
int num = 7;
for (i = 0; i < num; i++) {
for (j = 0; j < num; j++) {
if (isConditionMatch(num, i, j)) {
System.out.print("V");
} else {
System.out.print(" ");
}
}
System.out.println();
}
}
// this pattern will decide where to print 'V'
private static boolean isConditionMatch(int num, int i, int j) {
return (i + j == (num - 1) / 2 || j - i == (num - 1) / 2);
}
}
Output:
V
V V
V V
V V

How do I simplify these For-loops to save lines of code? [closed]

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Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 8 years ago.
Improve this question
The output of the code displays the following:
The code below seems pretty funky to me, even as a newbie. I imagine the code can be done more efficiently or at least lines of code can be saved without having to whip out so many loops.
If anyone can provide a cleaner solution, thanks in advance.
public class diamond {
public static void main(String[] args) {
for (int c=1; c<=10; c++) {
for (int d=1; d<=11-c; d++) {
System.out.print("*");
}
for (int e=2; e<c*2; e++) {
System.out.print(" ");
}
for (int i=1; i<=11-c; i++) {
System.out.print("*");
}
System.out.println();
}
for (int f=2; f<=10; f++) {
for (int g=1; g<=f; g++) {
System.out.print("*");
}
for (int h=2; h<22-f*2; h++) {
System.out.print(" ");
}
for (int j=1; j<=f; j++) {
System.out.print("*");
}
System.out.println();
}
}
}

The key is to notice repetitive patterns in your code and factor it out.
You could use a helper method to print a series of N characters:
public static void printNTimes(char value, int n) {
for (int i = 0; i < n; i++) {
System.out.print(value);
}
}
You can generalize the approach by using constants for the characters involved and the size of the diamond.
private static final char OuterChar = '*';
private static final char InnerChar = ' ';
private static final int Size = 10;
And add another helper method to print a row with N instances of one character on the outside, and 2 * (Size - N) characters on the inside:
private static void printRow(int n) {
printNTimes(OuterChar, n);
printNTimes(InnerChar, (Size - n) * 2);
printNTimes(OuterChar, n);
System.out.println();
}
Your code then becomes:
public class diamond
{
private static final char OuterChar = '*';
private static final char InnerChar = ' ';
private static final int Size = 10;
public static void printNTimes(char value, int n) {
for (int i = 0; i < n; i++) {
System.out.print(value);
}
}
private static void printRow(int n) {
printNTimes(OuterChar, n);
printNTimes(InnerChar, (Size - n) * 2);
printNTimes(OuterChar, n);
System.out.println();
}
public static void main(String[] args) {
for (int c = Size; c >= 1; c--) {
printRow(c);
}
for (int c = 2; c <= Size; c++) {
printRow(c);
}
}
}

int max=9,min=10;
for(int i=0;i<19;i++){
for(int j=0;j<20;j++){
if(j<min || j>max){
System.out.print("*");
}
else{
System.out.print(" ");
}
}
if(i<9){
min--;
max++;
}
else {
min++;
max--;
}
System.out.println();
}

I find this rather clear but YMMV.
for( int i = 10; i >= 1; i-- ){
String s = "**********".substring(0, i);
System.out.printf( "%-10s%10s\n", s, s );
}
for( int i = 1; i <= 10; i++ ){
String s = "**********".substring(0, i);
System.out.printf( "%-10s%10s\n", s, s );
}

Since this is repeated within the loop:
for (int d=1; d<=11-c; d++)
{
System.out.print("*");
}
you could write it to a variable and print it out twice. That would eliminate two loops. (one subloop in each outer loop)

I like to wrap logic in code that is easy to read and maintain so instead of doing loads of nested for-loops I wrote a class with descriptive methods.
package se.wederbrand.stackoverflow.diamond;
import java.util.ArrayList;
import java.util.List;
public class Diamond {
final List<String> rows;
public static void main(String[] args) {
System.out.println(new Diamond(10));
}
public Diamond(int width) {
this.rows = new ArrayList<>();
for (int stars = 1; stars <= width; stars++) {
// add all rows, start from the middle and build around it
addRows(stars, width);
}
}
private void addRows(int stars, int width) {
String row = generateRow(stars, width);
// add on top
this.rows.add(0, row);
if (stars > 1) {
// add to bottom
this.rows.add(row);
}
}
private String generateRow(int stars, int width) {
String row = "";
int spaces = width - stars;
for (int j = 0; j < stars; j++) {
row += "*";
}
for (int j = 0; j < spaces; j++) {
row += " ";
}
for (int j = 0; j < stars; j++) {
row += "*";
}
return row;
}
#Override
public String toString() {
String diamond = "";
for (String row : rows) {
diamond += row + System.lineSeparator();
}
return diamond;
}
}

This is an fun question as you get to see how everybody takes a different approach to solving it. This way just gives you a string that is "padded" with another character on the other side.
public static void main(String[] args) {
for (int c = 1; c <= 10; c++) {
System.out.println(printPadded(11 - c, '*', (c - 1) * 2, ' '));
}
for (int f = 10; f >= 2; f--) {
System.out.println(printPadded(11 - f, '*', (f - 1) * 2, ' '));
}
}
public static String printPadded(int padCount, char padCharacter,
int middleCount, char middleCharacter) {
StringBuilder s = new StringBuilder(padCount * 2 + middleCount);
for (int i = 0; i < padCount; i++) {
s.append(padCharacter);
}
for (int i = 0; i < middleCount; i++) {
s.append(middleCharacter);
}
for (int i = 0; i < padCount; i++) {
s.append(padCharacter);
}
return s.toString();
}