I am new to learning Java and I am trying to print an unfilled diamond using asterisks. The height of the diamond has to be based on user input. My code currently prints out a filled diamond based on user input but I cannot figure out how to print an unfilled one. Every time I change one of the loops it messes something else up. All help is appreciated!
public static void diamond(){
int i = 0;
int j = 0;
int k = 0;
int height = 0;
Scanner in = new Scanner(System.in);
System.out.println("How tall do you want the diamond to be: ");
height = in.nextInt();
for (k = 1; k <= (height + 1) / 2; k++) {
for (i = 0; i < height - k; i++) {
System.out.print(" ");
}
for (j = 0; j < k; j++) {
System.out.print("* ");
}
System.out.println("");
}
for (k = ((height + 1) / 2); k < height; k++) {
for (i = 1; i < k; i++) {
System.out.print(" ");
}
for (j = 0; j < height - k; j++) {
System.out.print(" *");
}
System.out.println("");
}
}
Here is the method modified for printing an unfilled diamond. An if condition has been added to the inner loops.
public static void diamond() {
int i = 0;
int j = 0;
int k = 0;
int height = 0;
Scanner in = new Scanner(System.in);
System.out.println("How tall do you want the diamond to be: ");
height = in.nextInt();
for (k = 1; k <= (height + 1) / 2; k++) {
for (i = 0; i < height - k; i++) {
System.out.print(" ");
}
for (j = 0; j < k; j++) {
if (j == 0 || j == (k - 1)) {
System.out.print("* ");
} else {
System.out.print(" ");
}
}
System.out.println("");
}
for (k = ((height + 1) / 2); k < height; k++) {
for (i = 1; i < k; i++) {
System.out.print(" ");
}
for (j = 0; j < height - k; j++) {
if (j == 0 || j == (height - k - 1)) {
System.out.print(" *");
} else {
System.out.print(" ");
}
}
System.out.println("");
}
}
Related
How to make this pattern
if input N = 5
Output :
Mine is like this, it become 2N
if input N = 5
Output
Here's my code
int i,j;
for(i = 0; i <= n; i++)
{
for(j = 1; j <= n - i; j++)
System.out.print(" ");
for(j = 1; j <= 2 * i - 1; j++)
System.out.print("*");
System.out.print("\n");
}
for(i = n - 1; i >= 1; i--)
{
for(j = 1; j <= n - i; j++)
System.out.print(" ");
for(j = 1; j <= 2 * i - 1; j++)
System.out.print("*");
System.out.print("\n");
}
What should i fix??
You can check odd numbers in your loop. Please see the following example:
public static void main(String[] args) {
printPattern(5);
}
private static void printPattern(int n) {
int i, j;
for (i = 0; i <= n; i++) {
if (i % 2 != 0) {
for (j = 1; j <= (n - i)/2; j++) {
System.out.print(" ");
}
for (j = 0; j < i; j++) {
System.out.print("*");
}
System.out.println();
}
}
for (i = n - 1; i >= 1; i--) {
if (i % 2 != 0) {
for (j = 1; j <= (n - i)/2; j++) {
System.out.print(" ");
}
for (j = 0; j <i; j++) {
System.out.print("*");
}
System.out.println();
}
}
}
Instead of running these two loops from 0 to N twice. Just run half N/2 in each loop.
Example:
public static void main(String[] args) {
int n = 10;
for (int i = 0; i <= (n / 2 + 1); i++) {
for (int j = 1; j <= n - i; j++) System.out.print(" ");
for (int j = 1; j <= 2 * i - 1; j++) System.out.print("*");
System.out.print("\n");
}
// N/2
for (int i = n / 2 - 1; i >= 1; i--) {
for (int j = 1; j <= n - i; j++) System.out.print(" ");
for (int j = 1; j <= 2 * i - 1; j++) System.out.print("*");
System.out.print("\n");
}
}
This is the work that i done so far:I have to print diamond pattern which always starts with uppercase from string, which repeats,but not always starts from the beginning.
public static void main(String[] args) {
Scanner keyboard = new Scanner(System.in);
String userInput = keyboard.next();
userInput = Character.toUpperCase(userInput.charAt(0)) + userInput.substring(1);
int i;
int j;
if (userInput.length() % 2 != 0) {
for(i = 1; i < userInput.length(); i += 2) {
for(j = 0; j < userInput.length() - 1 - i / 2; ++j) {
System.out.print(" ");
}
for(j = 0; j < i; ++j) {
System.out.print(userInput.charAt(j));
}
System.out.println("");
}
for(i = userInput.length(); i > 0; i -= 2) {
for(j = 0; j < userInput.length() - 1 - i / 2; ++j) {
System.out.print(" ");
}
for(j = 0; j < i; ++j) {
System.out.print(userInput.charAt(j));
}
System.out.print("\n");
}
} else {
for(i = 2; i < userInput.length(); i += 2) {
for(j = 0; j < userInput.length() - 1 - i / 2; ++j) {
System.out.print(" ");
}
for(j = 0; j < i; ++j) {
System.out.print(userInput.charAt(j));
}
System.out.println("");
}
for(i = userInput.length(); i > 0; i -= 2) {
for(j = 0; j < userInput.length() - 1 - i / 2; ++j) {
System.out.print(" ");
}
for(j = 0; j < i; ++j) {
System.out.print(userInput.charAt(j));
}
System.out.print("\n");
}
}
}
For example my input is "Peter".
So my output is:
P
Pet
Peter
Pet
P
but it must be:
P
Ete
Rpete
Rpe
T
I dont know what to change to make this work
Here's a shorter version of your code:
public static void main(String[] args) {
String userInput = "Peter";
int length = userInput.length();
int m, j, i, n = 0;
for (m = length % 2 > 0 ? 1 : 2; m < length * 2; m += 2) {
i = m < length ? m : length * 2 - m;
for (j = 0; j < length - 1 - i / 2; ++j) {
System.out.print(" ");
}
for(j = 0; j < i; ++j) {
char c = userInput.charAt(n++ % length);
c = j == 0 ? Character.toUpperCase(c) : Character.toLowerCase(c);
System.out.print(c);
}
System.out.println("");
}
}
You need some few changes:
Declare int n=0; after int j;
Always print userInput.charAt(n++ % userInput.length()) instead of charAt(j)
In order to get only the first character in line in uppercase:
char c = userInput.charAt(n++ % userInput.length());
c = j == 0 ? Character.toUpperCase(c) : Character.toLowerCase(c);
System.out.print(c);
Check the modulo operator.
With these changes, you'll get this output:
P
Ete
Rpete
Rpe
T
Given the fact that the input itself gets printed in a cylic manner, we can make use out of it. My proposal would be to concatenate the input string and print out the substrings which are determined by the structure of the diamond pattern.
public static void main(String[] args) {
Scanner keyboard = new Scanner(System.in);
String userInput = keyboard.next();
String concatenated = userInput;
// build up the index array
int i, cumSum = 0;
ArrayList<Integer> helperIndex = new ArrayList<>();
for(i = 1; i < userInput.length(); i += 2) {
helperIndex.add(i);
cumSum += i;
}
for(i = userInput.length(); i > 0; i -= 2) {
helperIndex.add(i);
cumSum += i;
}
int numOfWordRepitition = cumSum / userInput.length() ;
for (i = 0; i < numOfWordRepitition; i++){
concatenated += userInput;
}
// print out diamond
String substr;
int prev = helperIndex.get(0);
int next = helperIndex.get(0);
substr = concatenated.substring(0 , helperIndex.get(0));
System.out.println(Character.toUpperCase(substr.charAt(0)) + substr.substring(1));
for(i = 1; i < userInput.length(); i++){
next += helperIndex.get(i);
substr = concatenated.substring(prev , next);
substr = Character.toUpperCase(substr.charAt(0)) + substr.substring(1);
System.out.println(substr);
prev = next;
}
}
How can i get this code to display the height correctly? So if the width of the diamond asterisk is 3, and the height is 5, then the diamond will look like this.
*
***
***
***
*
It just adds any excess height to the middle. Here is my code so far. It can do the width just fine.
public static void main(String[] args) {
int width, height, heightT;
Scanner scan = new Scanner(System.in);
while(true) {
System.out.println("Enter width of diamond (odd number between 0-19): ");
width = scan.nextInt();
if (width % 2 != 0) {
if (0 <= width && width <= 19) {
break;
}
}
}
while(true) {
System.out.println("Enter height of diamond (greater than or equal to width): ");
height = scan.nextInt();
if(height >= width) {
heightT = height - width;
break;
}
}
for(int i = 1; i < width + 1; i += 2) {
for(int j = 0; j < 9 - i / 2; j++)
System.out.print(" ");
for(int j = 0; j < i; j++)
System.out.print("*");
System.out.print("\n");
}
for(int i = width - 2; i > 0; i -= 2) {
for(int j = 0; j < 9 - i / 2; j++)
System.out.print(" ");
for(int j = 0; j < i; j++)
System.out.print("*");
System.out.print("\n");
}
}
When solving this type of logic you have to always look at the things that you know never change. In this case, 3 things never change:
1. The first line. Always equal to one asterisk.
2. The middle line. Always equal to width in asterisks.
3. The last line. Always equal to one asterisk.
Now, split the diamond in two by the middle row. Notice the total height will always be the height of the top part (or bottom) times 2 plus 1 (the middle row). You get something more less like this:
for(int i = 0; ((i*2)+1) <= height; i++){
//Print top
}
// Print middle row outside of loops or inside if you must.
for(int i = 0; ((i*2)+1) <= height; i++){
//Print bottom.
}
EDIT: This would only be true for diamonds where height is greater than or equal to the width.
EDIT: This code solves your problem (given height is greater than or equal to width). However, it does not handle width = 0 or width = 1 properly. I trust that would be trivial enough for you to do.
public static void main(String[] args) {
int height = 9, width = 9;
int spaces = (width - 1) / 2, asterisks = 1;
for(int i = 0;((i*2)) < height; i++){
for(int ii = 0;ii < spaces;ii++){
System.out.print(" ");
}
for(int ii = 0;ii < asterisks;ii++){
System.out.print("*");
}
spaces--;
if(asterisks < width)asterisks += 2;
System.out.println();
}
spaces = 0;
for(int i = 0; ((i*2)+1) < height; i++){
if(width < height){
for(int ii = 0;ii < spaces;ii++){
System.out.print(" ");
}
for(int ii = 0;ii < asterisks;ii++){
System.out.print("*");
}
}else{
for(int ii = 0;ii < (spaces + 1);ii++){
System.out.print(" ");
}
for(int ii = 0;ii < (asterisks - 2);ii++){
System.out.print("*");
}
}
spaces++;
asterisks -= 2;
System.out.println();
}
}
You can calculate the difference between height and width and reuse your logic in a while loop.
for(int i = 1; i < width + 1; i += 2) {
for(int j = 0; j < 9 - i / 2; j++)
System.out.print(" ");
for(int j = 0; j < i; j++)
System.out.print("*");
System.out.print("\n");
}
int dif = height-width;
while(dif !=0){
for(int i = width; i < width + 1; i += 2) {
for(int j = 0; j < 9 - i / 2; j++)
System.out.print(" ");
for(int j = 0; j < i; j++)
System.out.print("*");
System.out.print("\n");
}
dif--;
}
for(int i = width - 2; i > 0; i -= 2) {
for(int j = 0; j < 9 - i / 2; j++)
System.out.print(" ");
for(int j = 0; j < i; j++)
System.out.print("*");
System.out.print("\n");
}
Im working on a pyramid on Java. I did it with stars. But i want to do it with decreasing numbers. I'm using an input. Assume input is 5;
5
545
54345
5432345
543212345
My code is;
int size = 11;
for (int i = 1; i <= size; i=i+2) {
int spaceCount = (size - i)/2;
for(int j = 0; j< size; j++) {
if(j < spaceCount || j >= (size - spaceCount)) {
System.out.print(" ");
} else {
System.out.print("*");
}
}
System.out.println();
}
I'm very glad to for your attention. Thanks a lot.
int size = 11;
for (int i = 1; i <= size; i=i+2) {
int spaceCount = (size - i)/2;
for(int j = 0; j< size; j++) {
if(j < spaceCount || j >= (size - spaceCount)) {
System.out.print(" ");
} else {
System.out.print(n);
}
}
System.out.println();
}
Something like this ?
But this only works for numbers of 1 - 9.
int h = 2;
String spacing = h == 1 ? "" : String.format("%" + (h - 1) + "s", "");
StringBuilder s = new StringBuilder(String.valueOf(h));
System.out.printf("%s%s\n", spacing, s);
for(int i = h; i > 1; --i){
System.out.print(spacing.substring(0, i - 2));
s.insert(s.length() / 2 + 1, String.valueOf(i - 1) + String.valueOf(i));
System.out.println(s.toString());
}
How do I make this:
*******
-*****-
--***--
---*---
--***--
-*****-
*******
The following is my code that I have written to try to accomplish the above, but it is not working as expected:
public static void stars(/*int jmlBaris*/) {
for ( int i = 7; i >= 1; i-=2) {
for (int j = 1; j <= i; j++) {
System.out.print("*");
}
System.out.println("");
}
for (int i = 1; i <= 7; i+=2) {
for (int j = 1; j <= i; j++){
System.out.print("*");
}
System.out.println("");
}
}
public static void main(String[] args) {
stars();
}
}
This is how I might write it.
// three loops
public static void stars(int size) {
for (int y = 0; y < size; y++) {
for (int i = 0; i < y && i < size - y - 1; i++)
System.out.print(' ');
for (int i = Math.min(y, size - y - 1); i < Math.max(y + 1, size - y); i++)
System.out.print('*');
System.out.println();
}
}
or
// two loops
public static void stars(int size) {
for (int y = 0; y < size; y++) {
for (int x = 0; x < size; x++)
System.out.print(
(x >= y && x < size - y) ||
(x >= size - y - 1 && x <= y) ? '*' : ' ');
System.out.println();
}
}
or
// one loop
public static void stars(int size) {
for (int i = 0; i < size * size; i++) {
int y = i / size, x = i % size;
System.out.print(
(x >= y && x < size - y) ||
(x >= size - y - 1 && x <= y) ? '*' : ' ');
if (x == size - 1)
System.out.println();
}
}
Note: Whether this uses one, two or three loops, the time complexity is O(N^2). A simple way to determine this is the number of stars produced is O(N^2) no matter how it is done.
I would do something like this with substrings.
String a = "*******"; //7 stars
String blank = " "; //7 spaces
int j = 7;
for (int i = 0; i < 7; i++) {
if (i > j){
System.out.print(blank.substring(0,i));
System.out.println(a.substring(i,j));
}
else{
System.out.print(blank.substring(0,j));
System.out.println(a.substring(j,i));
}
j--;
}
System.out.println(a);
**Previous edit wouldn't have worked. Changes made.
This works.
Try something like this code I compiled on IDEOne (it seems to work, though):
http://ideone.com/9xZ1YB
class Main
{
public static void main(String[] args)
{
stars();
}
static void stars()
{
final int MAX_WIDTH = 7;
for (int i = 0; i < 7; ++i)
{
int width;
if (i < 3) width = MAX_WIDTH - i * 2;
else if (i > 3) width = (i - 3) * 2 + 1;
else width = 1;
// Before spaces
for (int j = 0; j < (MAX_WIDTH - width) / 2; ++j)
{
System.out.print(" ");
}
// Stars
for (int j = 0; j < width; ++j)
{
System.out.print("*");
}
// After spaces
for (int j = 0; j < (MAX_WIDTH - width) / 2; ++j)
{
System.out.print(" ");
}
System.out.println();
}
}
}
For a beginner in algorithms I would recommend you to break down the structure in sub-parts and then try to solve the pattern.
For this specific pattern it could be broken down into several triangles. Each triangle is then solved by different for loops as shown in the image below.
public static void printPattern(int num) {
// this loop generates first 4 lines
for (int i = 0; i < num / 2 + 1; i++) {
// draws the red triangle of '-'
for (int j = 0; j < i; j++) {
System.out.print("-");
}
// draws the green triangle of '*'
for (int j = i; j < num / 2 + 1; j++) {
System.out.print("*");
}
// draws the blue triangle of '*'
for (int j = i + 1; j < num / 2 + 1; j++) {
System.out.print("*");
}
// draws the orange triangle of '-'
for (int j = 0; j < i; j++) {
System.out.print("-");
}
System.out.println();
}
/* this loop generates last 3 lines */
for (int i = 0; i < num / 2; i++) {
// draws the green triangle of '-'
for (int j = i + 1; j < num / 2; j++) {
System.out.print("-");
}
// draws the red triangle of '*'
for (int j = 0; j < i + 2; j++) {
System.out.print("*");
}
// draws the orange triangle of '*'
for (int j = 0; j < i + 1; j++) {
System.out.print("*");
}
// draws the blue triangle of '-'
for (int j = i + 1; j < num / 2; j++) {
System.out.print("-");
}
System.out.println();
}
}
Using similar technique you could generate any pattern.
If I understood you right, your problem is to print indent in lines 2-7.
Imagine same problem with asterisk symbol replaced by 'x' and whitespace replaced by '-'. Then you need to draw
xxxxxxx
-xxxxx-
--xxx--
---x---
--xxx--
-xxxxx-
xxxxxxx
That means you should output 0, 1, 2 space(s) before asterisks in first, second, thrid strings respectively. I let details for you to figure them out.
public static void stars(/*int jmlBaris*/){
String starstr = "*";
String blank = "_";
int spaceBlank;;
for(int i=7; i>=1;i-=2){
spaceBlank = (7-i)*.5;
String starrep = StringUtils.repeat(starstr, i);
String blankrep = StrinUtils.repeat(blank, spacesBlank);
system.out.println(blankrep + starrep + blankrep);
}
for(int j=3 j<=7; j+=2){
spaceBlank = (7-j)*.5;
starrep = StringUtils.repeat(starstr, j);
String blankrep = StrinUtils.repeat(blank, spacesBlank);
system.out.println(blankrep + starrep + blankrep);
}
}
public static void main(String[] args){
stars();
}
You have little missing to put space on your code. I don't care about right space, who can see that? But left space is very important!!
Try this:
public static void stars(/*int jmlBaris*/) {
for ( int i = 7; i >= 1; i-=2) {
for (int k = 0; k < ((7-i) / 2); k++){ /* Missing Here */
System.out.print(" "); /* Missing Here */
} /* Missing Here */
for (int j = 1; j <= i; j++) {
System.out.print("*");
}
System.out.println("");
}
for (int i = 1; i <= 7; i+=2) {
for (int k = 0; k < ((7-i) / 2); k++){ /* Missing Here */
System.out.print(" "); /* Missing Here */
} /* Missing Here */
for (int j = 1; j <= i; j++){
System.out.print("*");
}
System.out.println("");
}
}
int N = 7;
for (int y=0; y<N; y++)
{
for (int x=0; x<N; x++)
System.out.print( (y-x)*(N-y-x-1)<=0 ? '*' : '-');
System.out.println();
}
or, more symmetrically,
int n = 3;
for (int y=-n; y<=n; y++)
{
for (int x=-n; x<=n; x++)
System.out.print( y*y>=x*x ? '*' : '-');
System.out.println();
}