6 replies to this topic

[arunjib]

i want to get following out for a java program... how i should start my study?


output of the program:

How many stars you want to print in 1st row ? 7

*******
******
*****
****
*****
******
*******

[eafkuor]

If the user inputs n you will have to do something like this:

print '*' n times;

for(int i=0;i<n-2;i++)
   print a line;

print '*' n more times;

Now, think about that "print a line" statement.
If you need some more help just ask =)

[arunjib]

i applied the code as follows---

for(i=0;i<n;i++)
System.out.print("*");
for(i=0;i<n-2;i++)
System.out.println();
System.out.print("*");

but output is not come. i need some spaces to print please give me more clue.

If the user inputs n you will have to do something like this:

print '*' n times;

for(int i=0;i<n-2;i++)
   print a line;

print '*' n more times;

Now, think about that "print a line" statement.
If you need some more help just ask =)

[eafkuor]

String y=JOptionPane.showInputDialog("Number: ");

		int n=Integer.parseInt(y);

		

		for(int i=0;i<n;i++)System.out.print("*");

		System.out.println();

		

		int j;

		for(j=1;j<n/2;j++){

			int spaces=j;int middle=n-2*spaces-2; //you put the first '*' after j spaces, the second one after another n-2spaces-2

			for(int k=0;k<spaces;k++)System.out.print(" ");

			System.out.print("*");

			for(int k=0;k<middle;k++)System.out.print(" ");

			System.out.println("*");

		}

		if(n%2!=0){//you print the middle '*' only if n is odd

			for(int k=0;k<j;k++)System.out.print(" ");

			System.out.println("*");

		}

		for(j--;j>0;j--){

			int spaces=j;int middle=n-2*spaces-2;

			for(int k=0;k<spaces;k++)System.out.print(" ");

			System.out.print("*");

			

			for(int k=0;k<middle;k++)System.out.print(" ");

			System.out.println("*");

		}

		

		for(int i=0;i<n;i++)System.out.print("*");

	}

[arunjib]

Thank you very much for the code. There is only one logical error [if we input even number the shape will not come] in the above code. I just applied the following code

if(n%2==0)
n++; 

String y=JOptionPane.showInputDialog("Number: ");
		int n=Integer.parseInt(y);
		
		for(int i=0;i<n;i++)System.out.print("*");
		System.out.println();
		
		int j;
		for(j=1;j<n/2;j++){
			int spaces=j;int middle=n-2*spaces-2; //you put the first '*' after j spaces, the second one after another n-2spaces-2
			for(int k=0;k<spaces;k++)System.out.print(" ");
			System.out.print("*");
			for(int k=0;k<middle;k++)System.out.print(" ");
			System.out.println("*");
		}
		if(n%2!=0){//you print the middle '*' only if n is odd
			for(int k=0;k<j;k++)System.out.print(" ");
			System.out.println("*");
		}
		for(j--;j>0;j--){
			int spaces=j;int middle=n-2*spaces-2;
			for(int k=0;k<spaces;k++)System.out.print(" ");
			System.out.print("*");
			
			for(int k=0;k<middle;k++)System.out.print(" ");
			System.out.println("*");
		}
		
		for(int i=0;i<n;i++)System.out.print("*");
	}

[eafkuor]

Thank you very much for the code. There is only one logical error [if we input even number the shape will not come] in the above code. I just applied the following code

if(n%2==0)
n++; 

Oh well, you didn't specify the behaviour for even numbers so I just assumed it

[arunjib]

yes that was my fault that i did not specified...

Oh well, you didn't specify the behaviour for even numbers so I just assumed it