Java For Loop triangle pattern

Question

Hey I' m trying to create a pattern that's suppose to output multiples of 5 in a pattern like this:

5 10 15 20 25
  30 40 45 50
     55 60 65
        70 75
           80

but my output is like this

5 10 15 20 25                                                                                                                                 
 30 35 40 45                                                                                                                                  
  50 55 60                                                                                                                                    
   65 70                                                                                                                                      
    75

but when i put asterisks in the print :

here's my code:

import java.util.Scanner;

public class Main
{
    public static void main(String[] args) {

    int n = 5;
    int x =5;

    for(int i = n; i>=1; i--){

        for(int j = n-1; j>=i; j--){
            System.out.print(" ");
        }
        for(int k = 1; k<=i; k++){
            System.out.print(x+" ");
            x+=5;

        }

        System.out.println();
    }


    }
}

can somebody help me? i spent almost 3 hours trying to figure this out. any help would be appreciated. thanks!

I think your output is missing 35

ControlAltDel
– ControlAltDel

2019-11-18 15:08:26 +00:00
Commented Nov 18, 2019 at 15:08 — ControlAltDel
– ControlAltDel, Commented Nov 18, 2019 at 15:08

Arvind Kumar Avinash · Accepted Answer · 2019-11-18 16:56:20Z

2

The cleanest way to achieve what you want is to do is by using printf as shown below:

public class Main {
    public static void main(String[] args) {
        int n = 5;
        int x = 5;

        for (int i = n; i >= 1; i--) {
            for(int j=1;j<n-i+1;j++)
                System.out.printf("%3s"," ");
            for (int k = 1; k <= i; k++) {
                System.out.printf("%3d",x);
                x += 5;
            }
            System.out.println();
        }
    }
}

Output:

  5 10 15 20 25
    30 35 40 45
       50 55 60
          65 70
             75

Update:

If you are not comfortable with printf, you can use the following solution:

public class Main {
    public static void main(String[] args) {
        int n = 5;
        int x = 5;
        String space=" ";
        for (int i = n; i >= 1; i--) {
            for(int j=1;j<(n-i)*3;j++)
                System.out.print(space);
            for (int k = 1; k <= i; k++) {
                System.out.print(x+space);
                x += 5;
            }
            System.out.println();
        }
    }
}

Output:

5 10 15 20 25 
  30 35 40 45 
     50 55 60 
        65 70 
           75

edited Nov 18, 2019 at 16:56

answered Nov 18, 2019 at 16:19

Arvind Kumar Avinash

81.1k10 gold badges98 silver badges144 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Arvind Kumar Avinash Over a year ago

%4s specifies a length of 4 characters within which the given string will be printed. %4d specifies a length of 4 digits within which the given integer will be printed. I recommend you go through this tutorial.

Francesco Sollazzi · Accepted Answer · 2019-11-18 15:28:15Z

You write three characters at a time (space, first digit, second digit), so you need to print three spaces to have the correct results.

Basically your same code, but with three spaces int the System.out.print:

for(int i = n; i>=1; i--){

    //This is the same loop, but written in a different way.
    for(int j = 0; i < n-i; j++){
        System.out.print("   "); //THREE SPACES HERE
    }
    for(int k = 1; k<=i; k++){
        System.out.print(x+" ");
        x+=5;

    }

    System.out.println();
}

Now, you are also printing the 5 at the start, which is one digit long, so you need another space before. So you need a conditional structure in order to do this:

//This is the same loop, but written in a different way.
for(int j = 0; i < n-i; j++){
    if(j == 0 && x <= 5) //First cycle (remember 5, which is 1 digit)
        System.out.print("  "); //TWO SPACES HERE
    else
        System.out.print("   "); //THREE SPACES HERE
}

Note that this only works with 2 digits numbers so you need to do a similar thing like the one we used with the number five if you're gonna use also 3 or more digits numbers.

Stephan Hogenboom · Accepted Answer · 2019-11-18 15:54:54Z

I think this exercise is also a good moment to practice with System.out.printf()

Here is how i would do this:



public static void main(String[] args) {                   
    int x = 5;                                             
    int n = 35;                                            
    int max = calculateTotalNumbers(n) * x;  // calculate the highest number              
    int maxLenght = String.valueOf(max).length(); //calculate the numbers of digits in the highest number         

    for(int i = n; i>=1; i--){                             
        for (int j = 0; j < n - i; j++) {      
            //makes sure you will have the same length spaces everywhere            
            System.out.printf("%1$"+maxLenght+"s ", "");   
        }                                                  
        for (int k = 1; k <= i; k++) { 
            //this formatting will ensure every digit has the same length with padding included. Check out the javadoc of System.out.printf();                     
            System.out.printf("%" + maxLenght + "d ", x);  
            x += 5;                                        

        }                                                  
        System.out.println();                              
    }                                                      
}                                                          

// this method will calculate the total number of numbers you will print in the triangle
private static int calculateTotalNumbers(int n) {
    if (n <= 0) return 0;
    else return (n + calculateTotalNumbers(n -1));
}

Yukun Li · Accepted Answer · 2019-11-18 16:09:46Z

-1

public class temp {
    public static void main(String[] args) {
        int n = 5;
        int p = 1;
        for (int i = 0; i < n ; i ++){
            String curr = "";
            for (int j = 0 ; j < n - (n - i); j ++){
                curr += "  ";
                if (j > 0) {
                    curr += " ";
                }
            }
            for (int j = i; j < n; j ++){
                curr += Integer.toString(n * p);
                curr += " ";
                p += 1;
            }
            System.out.println(curr);
        }

    }
}

answered Nov 18, 2019 at 16:09

Yukun Li

2541 silver badge6 bronze badges

Collectives™ on Stack Overflow

Java For Loop triangle pattern

4 Answers 4

1 Comment

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

1 Comment

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related