Printing s as triangles in Java

Question

My assignment in my Java course is to make 3 triangles  One left aligned  one right aligned  and one centered  I have to make a menu for what type of triangle and then input how many rows is wanted  The triangles have to look like this                                                         So far I was able to do the left aligned triangle but I can t seem to get the other two  I tried googling but nothing turned up  Can anyone help  I have this so far   import java util    public class Prog673A       public static void leftTriangle                 Scanner input   new Scanner  System in           System out print  How many rows              int rows   input nextInt            for  int x   1  x  lt   rows  x                          for  int i   1  i  lt   x  i                                  System out print                                 System out println                          public static void rightTriangle                 Scanner input   new Scanner  System in           System out print  How many rows              int rows   input nextInt            for  int x   1  x  lt   rows  x                          for  int i   1  i  gt   x  i--                                System out print                                 System out println                           public static void centerTriangle                    public static void main  String args                   Scanner input   new Scanner  System in           System out println  Types of Triangles            System out println   t1  Left            System out println   t2  Right            System out println   t3  Center            System out print  Enter a number              int menu   input nextInt            if  menu    1              leftTriangle            if  menu    2              rightTriangle            if  menu    3              centerTriangle              Sample Output   Types of Triangles 1   Left 2   Right 3   Center Enter a number  1-3    3 How many rows   6

User · Answer

I know this is pretty late but I want to share my solution.

public static void main(String[] args) {
    String whatToPrint = "aword";
    int strLen = whatToPrint.length(); //var used for auto adjusting the padding
    int floors = 8;
    for (int f = 1, h = strLen * floors; f < floors * 2; f += 2, h -= strLen) {
        for (int k = 1; k < h; k++) {
                System.out.print(" ");//padding
            }
        for (int g = 0; g < f; g++) {
            System.out.print(whatToPrint);
        }
        System.out.println();
    }
}

The spaces on the left of the triangle will automatically adjust itself depending on what character or what word you want to print.

if whatToPrint = "x" and floors = 3 it will print

x xxx xxxxx If there's no automatic adjustment of the spaces, it will look like this (whatToPrint = "xxx" same floor count)

xxx xxxxxxxxx xxxxxxxxxxxxxxx

So I made add a simple code so that it will not happen.

For left half triangle, just change strLen * floors to strLen * (floors * 2) and the f +=2 to f++.

For right half triangle, just remove this loop for (int k = 1; k < h; k++) or change h to 0, if you choose to remove it, don't delete the System.out.print(" ");.

User · Answer

This is the least complex program  which takes only 1 for loop to print the triangle  This works only for the center triangle  but small tweaking would make it work for other s as well -   import java io DataInputStream   public class Triangle       public static void main String a    throws Exception          DataInputStream in   new DataInputStream System in            int n   Integer parseInt in readLine             String b   new String new char n   replaceAll   0                 String s                for int i 1  i lt  n  i                 System out print b               System out println s               s                      b   b substring 0  n-i               System out println

User · Answer

1  Normal triangle  package test1     class Test1         public static void main String args                    int n 5       for int i 0 i lt n i                     for int j 0 j lt  n-i j                             System out print                            for int k 0 k lt  2 i k                        System out print                            System out println   n                      2  right angle triangle  package test1     class Test1         public static void main String args                    int n 5       for int i 0 i lt n i                     for int j 0 j lt  n-i j                             System out print                            for int k 0 k lt  i k                        System out print                            System out println   n                                  3  Left angle triangle  package test1     class Test1         public static void main String args                    int n 5       for int i 0 i lt n i                     for int j 0 j lt  i j                             System out print                            System out println   n

User · Answer

For center triangle        Scanner sc   new Scanner System in         int n sc nextInt          int b  n-1  2          for int i 1 i lt  n i           int t  i        for int k 1 k lt  b k           System out print                       if i  1           t i 2-1                  for int j 1 j lt  t j            System out print              if j  t          System out print                                  System out println                b b-2                output

User · Answer

Left alinged triangle-               from above pattern we come to know that- 1 we need to print pattern containing n rows  for above pattern n is 4   2 each  row contains star and no of stars i each row is incremented by 1  So for Left alinged triangle we need to use 2 for loop  1st  for loop  for printing n row  2nd   for loop for printing stars in each rows      Code for  Left alinged triangle-   public static void leftTriangle                here  no of rows is 4  for  int a 1 a lt  4 a      for loop for row        for  int b 1 b lt  a b   for loop for column     System out print           System out println           Right  alinged triangle-                from above pattern we come to know that- 1 we need to print pattern containing n rows  for above pattern n is 4    2 In each  row we need to print spaces followed by a star  amp  no of spaces            in each row is decremented by 1   So for Right alinged triangle we need to use 3 for loop   1st  for loop  for printing n row   2nd   for loop for printing spaces   3rd  for loop  for printing stars   Code for Right alinged triangle -  public void rightTriangle            here 1st print space and then print star   for  int a 1 a lt  4 a      for loop for row      for  int c  3 c gt  a c--    for loop fr space       System out print           for  int d 1 d lt  a d      for loop for column      System out print              System out println               Center Triangle-                 from above pattern we come to know that-    1 we need to print pattern containing n rows  for above pattern n is 4      2 Intially in each  row we need to print spaces  followed by a star  amp  then   again a space   NO of spaces in each row at start is decremented by 1     So for Right alinged triangle we need to use 3 for loop     1st  for loop  for printing n row     2nd   for loop for printing spaces     3rd  for loop  for printing stars   Code for center Triangle-  public  void centerTriangle        for  int a 1 a lt  4 a      for lop for row      for  int c  4 c gt  a c--    for loop for space     System out print         for  int b 1 b lt  a b      for loop for column   System out print             System out println           CODE FOR PRINTING ALL 3 PATTERNS -      public class space4           public static void leftTriangle                        here  no of rows is 4      for  int a 1 a lt  4 a      for loop for row             for  int b 1 b lt  a b   for loop for column             System out print               System out println        public static void rightTriangle            here 1st print space and then print star   for  int a 1 a lt  4 a      for loop for row      for  int c  3 c gt  a c--    for loop for space       System out print           for  int d 1 d lt  a d      for loop for column      System out print              System out println            public static void centerTriangle        for  int a 1 a lt  4 a      for lop for row      for  int c  4 c gt  a c--    for loop for space     System out print         for  int b 1 b lt  a b      for loop for column   System out print             System out println       public static void main  String args       space4 s new space4    s leftTriangle    s rightTriangle    s centerTriangle

User · Answer

This will print stars in triangle        public class printstar  public static void main  String args     int m   0  for int i 1 i lt  4 i     for int j 1 j lt  4-i j     System out print        for  int n 0 n lt  i m n     if  n 2  0   System out print        else  System out print          m   m 1  System out println               Reading and understanding this should help you with designing the logic next time

User · Answer

Find the following   it will help you to print the complete triangle   package com raju arrays    public class CompleteTriange    public static void main String   args        int nuberOfRows   10        for int row   0  row lt nuberOfRows row                for int leftspace  0 leftspace lt  nuberOfRows-row  leftspace                   System out print                             for int star   0 star lt 2 row 1 star                   System out print                             for int rightSpace  0 rightSpace lt  nuberOfRows-row  rightSpace                   System out print                             System out println

User · Answer

public static void main String   args         System out print  Enter the number          Scanner userInput   new Scanner System in       int myNum   userInput nextInt        userInput close         System out println  Centered Triange        for  int i   1  i  lt   myNum  i  1     This tells how many lines to print  height           for  int k   0  k  lt   myNum-i   k  1     Prints spaces before the                 System out print                          for  int j   0  j  lt  i  j        Prints a     followed by                     System out print                           System out println        Next Line                 System out println  Left Triange        for  int i   1  i  lt   myNum  i  1     This tells how many lines to print  height           for  int j   0  j  lt  i  j        Prints the     first in each line then spaces                System out print                           System out println        Next Line                     System out println  Right Triange        for  int i   1  i  lt   myNum  i  1     This tells how many lines to print  height           for  int k   0  k  lt   myNum-i   k  1     Prints spaces before the                 System out print                           for  int j   0  j  lt  i  j  1      Prints the     first in each line then a                    System out print                           System out println        Next Line

User · Answer

public class triangle       public static void main   String arg               System out print  Enter Triangle Size               int num 0          try              num Integer parseInt  read readLine                catch Exception Number               System out println  Invalid Number                           for int i 1 i lt  num i                     for int j 1 j lt num- i-1  j                         System out print                                         for int k 1 k lt  i k                         System out print                           for int k1 1 k1 lt k k1  k                            System out print                                                               System out println

User · Answer

well for the triangle   you need to have three loops in place of two   one outer loop to iterate the no of line two parallel loops inside the main loop first loop prints decreasing no of loops second loop prints increasing no of    well i could give the exact logic as well   but its better if you try first just concentrate how many spaces and how many    u need in every line relate the no of symbols with loop iterating no of lines and you re done       if it bothers more   let me know   i ll explain with logic and code as well

User · Answer

Ilmari Karonen has good advice  and I d just like to generalize it a bit  In general  before you ask  how can I get a computer to do this   ask  how would I do this    So  if someone gave you an empty Word document and asked you to create the triangles  how would you go about doing it  Whatever solution you come up with  it s usually not hard to translate it to Java  or any other programming language   It might not be the best solution  but  hopefully   it ll work  and it may point you to a better solution   So for instance  maybe you would say that you d type out the base  then go up a line  then type the next highest line  etc  That suggests that you can do the same in Java -- create a list of Strings  base-to-top  and then reverse them  That might suggest that you can just create them in reverse order  and then not have to reverse them  And then that might suggest that you don t need the list anymore  since you ll just be creating and printing them out in the same order -- at which point you ve come up with essentially Ilmari Karonen s advice   Or  maybe you d come up with another way of doing it -- maybe you d come up with Ilmari Karonen s idea more directly  Regardless  it should help you solve this and many other problems

User · Answer

This is for normal triangle  for  int i   0  i  lt  5  i                          for  int j   5  j  gt  i  j--                                System out print                                 for  int k   1  k  lt   i   1  k                      System out print                                  System out print   n                   This is for left triangle  just removed space before printing    for  int i   0  i  lt  5  i                          for  int j   5  j  gt  i  j--                                System out print                                 for  int k   1  k  lt   i   1  k                      System out print                                 System out print   n

User · Answer

For left aligned right angle triangle you could try out this simple code in java   import java io    import java util     public class Solution        public static void main String   args          Scanner sc new Scanner System in         int size sc nextInt           for int i 0 i lt size i                for int k 1 k lt size-i k                        System out print                                   for int j size j gt  size-i j--                   System out print                               System out println

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package apple   public class Triangle   private static final int row   3   public static void main String   strings       printLeftTrangle        System out println        printRightTrangle        System out println        printTrangle           Pattern will be                                        public static void printLeftTrangle         for int y 1 y lt  row y          for int x 1 x lt  y x             System out print            System out println                 Pattern will be                                             public static void printRightTrangle        for int y 1 y lt  row y             for int space row space gt y space--              System out print               for int x 1 x lt  y x                System out print               System out println                 Pattern will be                             public static void printTrangle         for int y 1  star 1 y lt  row y   star   2           for int space row space gt y space--              System out print               for int x 1 x lt  star x                System out print               System out println

User · Answer

import java util Scanner   public class A        public void triagle center int max    max means maximum star having         int n max 2          for int m 0 m lt   2 n -1  m      for upper star             System out print                         System out println                for int j 1 j lt  n j                 for int i 1 i lt  n-j  i                     System out print                                  for int k 1 k lt  2 j k                 System out print                                   System out println                           public void triagle right int max           for int j 1 j lt  max j                 for int i 1 i lt  j  i                     System out print                                   System out println                         public void triagle left int max           for int j 1 j lt  max j                 for int i 1 i lt  max-j  i                     System out print                                  for int k 1 k lt  j  k                     System out print                                   System out println                         public static void main String args             A a new A            Scanner input   new Scanner  System in           System out println  Types of Triangles            System out println   t1  Left            System out println   t2  Right            System out println   t3  Center            System out print  Enter a number              int menu   input nextInt            Scanner input1   new Scanner  System in           System out print  maximum Stars in last row              int row   input1 nextInt            if  menu    1              a triagle left row           if  menu    2              a triagle right row           if  menu    3              a triagle center row

User · Answer

Hint  For each row  you need to first print some spaces and then print some stars  The number of spaces should decrease by one per row  while the number of stars should increase   For the centered output  increase the number of stars by two for each row

User · Answer

Question                                    Answer       int i a j      i 5      while  i gt  3                a 1          while  a lt  i                         System out print                   a                      j 10          while  j 2 gt  i                        System out print                   --j                    System out println              i--             Enjoy

User · Answer

You might be interested in this too          Scanner sc   new Scanner System in         int n sc nextInt          int b 0        for int i n i gt  1 i--         if i  n         for int k 1 k lt  b k           System out print                                      for int j i j gt  1 j--          System out print              if i  1          System out print                                      System out println           b b 2              Output     5

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for int i 1 i lt  5 i                  for int j 5 j gt  i j--                        System out print                         for int j 1 j lt  i j                          System out print                          for int j 1 j lt  i-1 j                          System out print                         System out println

User · Answer

For the right triangle  for each row     First  You need to print spaces from  0 to rowNumber - 1 - i   Second  You need to print    from rowNumber - 1 - i to rowNumber    Note  i is the row index from 0 to rowNumber and rowNumber is number of rows   For the centre triangle  it looks like  right triangle  plus adding     according to the row index  for ex   in first row you will add nothing because the index is 0   in the second row you will add one        and so on

User · Answer

a     b          c     d                                                                                                                                                                                                                                                                       int line  int star  System out println  Triangle a            for  line   1  line  lt   10  line                           for  star   1  star  lt   line  star                                    System out print                                   System out println                System out println  Triangle b               for  line   1  line  lt   10  line                           for  star   1  star  lt   10  star                            if line lt star                  System out print                         else                   System out print                                 System out println                System out println  Triangle c               for  line   1  line  lt   10  line                           for  star   1  star  lt   10  star                            if line lt  star                  System out print                           else                     System out print                                 System out println                System out println  Triangle d               for  line   1  line  lt   10  line                           for  star   1  star  lt   10  star                            if line gt 10-star                  System out print                         else                   System out print                                 System out println

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