Develop Reference

How to print a diamond pattern outline with C#

Here's the code of a solid diamond and I want to remove the middle and leave the edges.
From this,
to this,
public void DiamondOne()
{
int i, j, count = 1, number;
Console.Write("Enter number of rows:");
number = int.Parse(Console.ReadLine());
count = number - 1;
for (j = 1; j <= number; j++)
{
for (i = 1; i <= count; i++)
Console.Write(" ");
count--;
for (i = 1; i <= 2 * j - 1; i++)
Console.Write("*");
Console.WriteLine();
}
count = 1;
for (j = 1; j <= number - 1; j++)
{
for (i = 1; i <= count; i++)
Console.Write(" ");
count++;
for (i = 1; i <= 2 * (number - j) - 1; i++)
Console.Write("*");
Console.WriteLine();
}
Console.ReadLine();
}

I would go with something like this:
public void Diamond()
{
Console.WriteLine("Enter number of rows:");
bool isNumber = int.TryParse(Console.ReadLine(), out int rowsNr);
if (!isNumber)
{
Console.WriteLine("Not a number!");
return;
}
// print the upper half
for (int rowIndex = 0; rowIndex < rowsNr - 1; rowIndex++)
{
for (int colIndex = 0; colIndex <= 2 * rowsNr; colIndex++)
{
if (colIndex == Math.Abs(rowsNr - rowIndex) || colIndex == Math.Abs(rowsNr + rowIndex))
{
Console.Write("*");
}
else
{
Console.Write(" ");
}
}
Console.WriteLine();
}
// print the lower half
for (int rowIndex = 1; rowIndex <= rowsNr; rowIndex++)
{
for (int colIndex = 0; colIndex <= 2 * rowsNr; colIndex++)
{
if (colIndex == rowIndex || colIndex == 2 * rowsNr - rowIndex)
{
Console.Write("*");
}
else
{
Console.Write(" ");
}
}
Console.WriteLine();
}
}
Basically you are looking for the x and y coordinates. Each of the 4 edges has its own equation (the upper-left one is x == y for instance) and you check for these while you iterate. I split the code in two parts, one for the upper half and one for the lower half. It's more readable and you don't put together too many if statements and lose the meaning of the code.

This is what I came up with:
// Get the number of rows
int rows;
do
{
Console.WriteLine("Enter number of rows:");
} while (!int.TryParse(Console.ReadLine(), out rows));
// Print diamond
DiamondOne(rows, Console.Out);
// Wait for key press
Console.WriteLine("Press any key to exit");
Console.ReadKey(true);
static void DiamondOne(int rows, TextWriter output)
{
for (int currentRow = 0; currentRow < rows; currentRow++)
{
OutputRow(rows, output, currentRow);
}
for (int currentRow = rows - 2; currentRow >= 0; currentRow--)
{
OutputRow(rows, output, currentRow);
}
}
static void OutputRow(int rows, TextWriter output, int currentRow)
{
int indentation = rows - currentRow - 1;
int diamondCentre = Math.Max((currentRow * 2) - 1, 0);
output.Write(new string(' ', indentation));
output.Write('*');
output.Write(new string(' ', diamondCentre));
if (currentRow != 0) output.Write('*');
output.WriteLine();
}

C# program for printing numbers triangle?

class Triangle
{
static void Main(string[] args)
{
int i,j,k,odd=1,size,s=0;
Console.Write("Enter the Size:");
size = Convert.ToInt32(Console.ReadLine());
int nofSpaces=size-1;
for (i = 1; i <= size; i++)
{
for (k = 1; k <= nofSpaces; k++)
{
Console.Write(" ");
}
for (j = 1; j <= odd; j++)
{
if (i >= j)
{
s = s + 1;
}
else
{
s = s - 1;
}
Console.Write(s);
}
Console.Write("\n");
odd = odd + 2;
nofSpaces = nofSpaces - 1;
}
Console.ReadKey();
}
}
This is the code and it gives the following result:
1
232
34543
4567654
56789875
But I need the result like this:
1
121
12321
1234321
---------
Any help would be greatly appreciated. Thank you.

Add
s = 0;
at the right line in your code.

class Triangle
{
static void Main(string[] args)
{
int i,j,k,odd=1,size;
Console.Write("Enter the Size:");
size = Convert.ToInt32(Console.ReadLine());
int nofSpaces=size-1;
int s = 0;
for (i = 1; i <= size; i++)
{
int g = 0;
for (k = 1; k <= nofSpaces; k++)
{
Console.Write(" ");
}
for (j = 1; j <= odd; j++)
{
if (i >= j)
{
Console.Write(j);
g = j;
}
else
{
//for (int n = j-1; n >= i; n--)
//{
// Console.Write(n - 1);
//}
Console.Write(--g);
}
}
Console.Write("\n");
odd = odd + 2;
nofSpaces = nofSpaces - 1;
}
Console.ReadKey();
}
}
}
Thank you All!... The above code is working....

You should try this...
This is a simple example with for loops
class Triangle
{
static void Main(string[] args)
{
int size;
Console.Write("Enter the Size:");
size = Convert.ToInt32(Console.ReadLine());
for (int i = 0; i < size; i++)
{
for (int j = size ; j > i; j--)
{
Console.Write(" ");
}
for (int x = 1; x <= i; x++)
{
Console.Write(x);
}
for (int j = i-1; j > 0; j--)
{
Console.Write(j);
}
Console.WriteLine();
}
Console.ReadKey();
}
}

Please write as below
static void Main(string[] args)
{
int i, j, k, odd = 1, size, s = 0;
Console.Write("Enter the Size:");
size = Convert.ToInt32(Console.ReadLine());
int nofSpaces = size - 1;
for (i = 1; i <= size; i++)
{
for (k = 1; k <= nofSpaces; k++)
{
Console.Write(" ");
}
s = 0;
for (j = 1; j <= odd; j++)
{
if (i >= j)
{
s = s + 1;
}
else
{
s = s - 1;
}
Console.Write(s);
}
Console.Write("\n");
odd = odd + 2;
nofSpaces = nofSpaces - 1;
}
Console.ReadKey();
}

Using a while loop to create a pyramid in C#

I'm learning here some of C# still, but I have made a pyramid from asterisks with for loop:
using System;
namespace Nimi{
class Ohjelma{
static void Main(){
for(;;){
Console.Write("Anna korkeus: ");
string eka = Console.ReadLine();
int luku = int.Parse(eka);
//First, I made that if the number is 0 or lower, it will ask the number again.
//Hence the endless loop at start.
if(luku <= 0){
continue;
} else {
for (int i = 0; i < luku; i++ )
{
for (int k=i+1; k < luku; k++)
{
Console.Write(" ");
}
for (int j = 2*i+1; j > 0; j--)
{
Console.Write("*");
}
Console.WriteLine("");
}
break;
}
}
}
}
}
I'm just out of curiosity wanting to know how this would work with while-loop which I haven't been able to create still. The way I thought it would be:
using System;
namespace Nimi{
class Ohjelma{
static void Main(){
while(true){
// The While-loop version of endless loop. Not sure how different it is.
Console.Write("Anna korkeus: ");
string eka = Console.ReadLine();
int luku = int.Parse(eka);
if(luku <= 0){
continue;
} else {
int i = 0;
int j = i * 2 + 1;
int k = i+1;
while(i < luku)
{
while (j > 0){
while (k < luku){
Console.Write(" ");
k++;
}
Console.Write("*");
j--;
}
Console.WriteLine();
i++;
}
break;
}
}
}
}
}
Don't really work out. It only posts something like this (when value is 4:
*
What's the correct way to transfer from for-loop to while-loop to create a pyramid with asterisks?

This
using System;
namespace Nimi
{
class Ohjelma
{
static void Main()
{
for (; ; )
{
Console.Write("Anna korkeus: ");
string eka = Console.ReadLine();
int luku = int.Parse(eka);
//First, I made that if the number is 0 or lower, it will ask the number again.
//Hence the endless loop at start.
if (luku <= 0)
{
continue;
}
else
{
int i = 0;
while (i < luku)
{
int k = i + 1;
while (k < luku)
{
Console.Write(" ");
k++;
}
int j = 2 * i + 1;
while (j > 0)
{
Console.Write("*");
j--;
}
Console.WriteLine("");
i++;
}
break;
}
}
}
}
}
And remember: if your code is correctly formatted, it's easier to read. ^ED in Visual Studio to format everything.
(^ED means CTRL+E and then D (with the D you don't need the CTRL, it will work both ways)

for (int j = 2*i+1; j > 0; j--)
{
Console.Write("*");
}
becomes
{
int j = 2*i+1;
while (j > 0)
{
Console.Write("*");
j--;
}
}
Note that the "extra" curly braces preserve the locality of j, just like the for().

private static void pyramid()
{
int k = 10;
int j=0;
while(true)
{
int i = 0;
while(true)
{
if (i >= (k - j) && i <= (k + j))
{
Console.Write("*");
Console.Write("\t");
}
else
{
Console.Write("\t");
}
if (i > (j + k))
{
break;
}
i++;
}
Console.Write("\n");
if (j == (k - 1))
{
break;
}
j++;
}
}

C# Multiplication Table

So I'm attempting to print a multiplication table in C# however I can't quite figure out how to get what I need.
So far my program outputs the following:
1 2 3
2 4 6
3 6 9
However, I need it to output this:
0 1 2 3
1 1 2 3
2 2 4 6
3 3 6 9
I've tried a lot of different ways to get the second output however I can't quite figure it out. I'm not necessarily asking for an answer but if someone could point me in the right direction it would be much appreciated.
This is the code I have as of now:
static void Main(string[] args)
{
for (int i = 1; i <= 3; i++)
{
for (int j = 1; j <= 3; j++)
{
Console.Write(i * j + "\t");
}
Console.Write("\n");
}
Console.ReadLine();
}

for (int i = 0; i <= 3; i++)
{
Console.Write(i + "\t");
for (int j = 1; j <= 3; j++)
{
if (i>0) Console.Write(i * j + "\t");
else Console.Write(j + "\t");
}
Console.Write("\n");
}

int tbl= int.Parse(Console.ReadLine());
int j = int.Parse(Console.ReadLine());
for (int i=1; i<=10; i++)
{
for (int j=1;j<=10; j++)
{
Console.WriteLine("{0}*{1}={2}", i, j, (i * j));`enter code here`
}
}
Console.ReadLine();

You should skip both 0's.
for (int i = 0; i <= 3; i++)
{
for (int j = 0; j <= 3; j++)
{
Console.Write((i == 0? j : (j == 0? i : i*j)) + "\t");
}
Console.Write("\n");
}

You could try one of this three solutions.
Solution 1 (without if else statement):
static void Main(string[] args)
{
for (int i = 0; i <= 3; i++)
{
Console.Write("{0}\t", i);
for (int j = 1; j <= 3; j++)
{
Console.Write("{0}\t", i * j);
}
Console.WriteLine();
}
Console.ReadLine();
}
Solution 2 (With if else statement):
static void Main(string[] args)
{
for (int i = 0; i <= 3; i++)
{
for (int j = 1; j <= 3; j++)
{
if (i == 0)
{
Console.Write("{0}\t", i);
}
else
{
Console.Write("{0}\t", i * j);
}
}
Console.WriteLine();
}
Console.ReadLine();
}
Solution 3 (With short-hand if else statement):
static void Main(string[] args)
{
for (int i = 0; i <= 3; i++)
{
for (int j = 1; j <= 3; j++)
{
Console.Write("{0}\t", (i == 0) ? i : i * j);
}
Console.WriteLine();
}
Console.ReadLine();
}

for (int i = 0; i <= 3; i++)
{
for (int j = 0; j <= 3; j++)
{
if (i == 0)
{
Console.Write(j);
}
else
{
if(j == 0)
{
Console.Write(i);
}
else
{
Console.Write(i * j);
}
}
}
Console.Write("\n");
}

Console.WriteLine("Enter A Number");
int j = Convert.ToInt32(Console.ReadLine());
for (int i = 0 ; i <= 10; i++) {
Console.WriteLine("{1} X {0} = {2}",i,j,i*j);
Console.ReadLine();
}

public class Program
{
//int num;
public static void Main(string[] args)
{
int num,num1;
Console.WriteLine("enter a any number num");
num = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("enter any second number num1");
num1 = Convert.ToInt32(Console.ReadLine());
for(int i = num;i <= num1; i++)
{
for (int j = 1; j <= 10; j++)
{
Console.Write(i *j+ "\t");
}
}
Console.Write("\n");
}
}

using System;
/*
* Write a console-based application that displays a multiplication table of the product of
* every integer from 1 through 10 multiplied by every integer from 1 through 10. Save the
* file as DisplayMultiplicationTable.cs.
*/
namespace MultiplicationTable
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("\t\t\t\t\t\t\t\t\tMultiplication Table");
Console.WriteLine("------------------------------------------------------------------------------------------------------------------------------------------------------------");
const int END = 11;
for(int x = 1; x < END; x++)
{
for(int y = 1; y < END; y++)
{
int value = x * y;
Console.Write("{0} * {1} = {2}\t", y, x, value);
}
Console.WriteLine();
}
Console.ReadLine();
}
}
}
Output
Output of Code
I am attempting to complete the above code in a GUI. So far I have come up with the following code; but the output is not like the above output.
My Code for the GUI is as follows:
using System;
using System.Windows.Forms;
namespace DisplayMultiplicationTableGUI
{
public partial class Form1:Form
{
public Form1()
{
InitializeComponent();
}
private void ShowTableButton_Click(object sender, EventArgs e)
{
int a;
int b;
const int STOP = 11;
for(a = 1; a < STOP; a++)
{
for(b = 1; b < STOP; b++)
{
int value = a * b;
multiplicationTableLabel.Text += String.Format("{0} * {1} = {2} ", b, a, value);
}
multiplicationTableLabel.Text += "\n";
}
}
}
}

create asterisk tree with C#

Hello everyone
I try to solve asterisk tree problem
and found my code is not work correctly and can be improved.
This is output that expected
input : 5
*
* * *
* * * * *
* * *
*
input : 4
* * * *
* *
* * * *
and this is my code
static void Main(string[] args)
{
Console.Write("input:");
char input = Console.ReadKey().KeyChar;
if (char.IsDigit(input))
{
int couter = (int)char.GetNumericValue(input);
Console.WriteLine();
if (couter % 2 != 0)
{
for (int i = 1; i <= couter; i++)
{
for (int j = 3; j > i; j--)
{
Console.Write(" ");
}
for (int k = 1; k <= i; k++)
{
Console.Write(" *");
}
Console.WriteLine();
}
for (int i = couter - 1; i >= 3; i--)
{
for (int j = 1; j <= i; j++)
{
if (j <= couter - i)
{
Console.Write(" ");
}
else
{
Console.Write("* ");
}
}
Console.WriteLine();
}
}
else
{
for (int i = couter; i > 3; i--)
{
for (int j = 1; j <= i; j++)
{
if (couter - i >= j)
{
Console.Write(" ");
}
else
{
Console.Write("* ");
}
}
Console.WriteLine();
}
for (int i = couter - 1; i <= couter; i++)
{
for (int j = 0; j < i; j++)
{
Console.Write("* ");
}
Console.WriteLine();
}
}
}
}
Please could you help me to solve this problem.
Lately, I think I'm poor at algorithms and a little complex problem. Is anybody know useful link or how I can improve this skill, please let me know.
Thanks,

Check this page for input 5 (diamond) : http://www.dreamincode.net/forums/topic/126715-diamond-asterisk/
I've translated it to C# - now it displays diamonds with size that you set in variable 'rows':
int rows = 5;
StringBuilder sb = new StringBuilder();
// top part
for (int i = 1; i <= rows; i++)
{
for (int j = 1; j <= rows - i; j++)
sb.Append(' ');
for (int k = 1; k <= 2 * i - 1; k++)
sb.Append('*');
sb.AppendLine();
}
//bottom part
for (int n = rows - 1; n > 0; n--)
{
for (int l = 1; l <= rows - n; l++)
sb.Append(' ');
for (int m = 1; m <= 2 * n - 1; m++)
sb.Append('*');
sb.AppendLine();
}
Console.Write(sb.ToString());

I was initially reluctant to post it because it definitely smells like homework...
Anyway, here's a piece of working code:
static void Main(string[] args)
{
Console.Write("input:");
char input = Console.ReadKey().KeyChar;
if (char.IsDigit(input))
{
int couter = (int)char.GetNumericValue(input);
Console.WriteLine();
if (couter % 2 != 0)
PrintDiamond(couter);
else
PrintHourGlass(couter);
}
Console.ReadLine();
}
private static void PrintDiamond(int couter)
{
bool moreAsterisks = true;
for (int row = 0; row < couter; row++)
{
int nAsterisks = moreAsterisks ? (2 * row) + 1 : 2 * (couter - row - 1) + 1;
int nSpaces = (couter - nAsterisks) / 2;
if (row == (couter - 1) / 2)
moreAsterisks = false;
for (int i = 0; i < nSpaces; i++)
Console.Write(" ");
for (int i = 0; i < nAsterisks; i++)
Console.Write("*");
for (int i = 0; i < nSpaces; i++)
Console.Write(" ");
Console.WriteLine();
}
}
private static void PrintHourGlass(int couter)
{
bool moreAsterisks = false;
for (int row = 0; row < couter - 1; row++)
{
int nAsterisks = moreAsterisks ? couter - 2 * (couter - row - 2) : couter - (2 * row);
int nSpaces = (couter - nAsterisks) / 2;
if (row == (couter - 2) / 2)
moreAsterisks = true;
for (int i = 0; i < nSpaces; i++)
Console.Write(" ");
for (int i = 0; i < nAsterisks; i++)
Console.Write("*");
for (int i = 0; i < nSpaces; i++)
Console.Write(" ");
Console.WriteLine();
}
}
P.S.:
it works with any number, not just 4-5...

Here's a minified LINQ solution for your problem:
class Program
{
static void Main(string[] args)
{
Console.Write("input: ");
string line = Console.ReadLine();
int n;
if (!int.TryParse(line, out n))
{
Console.WriteLine("Enter a valid integer number.");
return;
}
for (int i = 0; i < n; i++)
{
int l = Math.Abs(n - i * 2 - 1) + 1;
if (n % 2 != 0) l = n - l + 1;
Console.Write(Enumerable.Repeat(" ", n - l).DefaultIfEmpty("").Aggregate((a, b) => a + b));
Console.WriteLine(Enumerable.Repeat("* ", l).DefaultIfEmpty("").Aggregate((a, b) => a + b));
}
}
}
It's pretty simple; inside the loop, first line calculates length of the i-th diamond row if input is even, second one corrects the calculation for odd input. The remaining two lines print i-th row using some LINQ tricks. If you don't like showing off with LINQ, you can replace thoose lines with regular for loops (which is probably going to be faster). Then the code would look like:
class Program
{
static void Main(string[] args)
{
Console.Write("input: ");
string line = Console.ReadLine();
int n;
if (!int.TryParse(line, out n))
{
Console.WriteLine("Enter a valid integer number.");
return;
}
for (int i = 0; i < n; i++)
{
int l = Math.Abs(n - i * 2 - 1) + 1;
if (n % 2 != 0) l = n - l + 1;
//Console.Write(Enumerable.Repeat(" ", n - l).DefaultIfEmpty("").Aggregate((a, b) => a + b));
//Console.WriteLine(Enumerable.Repeat("* ", l).DefaultIfEmpty("").Aggregate((a, b) => a + b));
for (int c = 0; c < n - l; c++) Console.Write(" ");
for (int c = 0; c < l; c++) Console.Write("* ");
Console.WriteLine();
}
}
}