create patten using C#

Vatsal Desai

11y1.2kVisual Basic .NET

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make spiral in C# console application. can any one provide code?

3 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes11y ago
Accepted answer
This code will draw that particular spiral:

using System;

class Spiral
{
static void Main()
{
for (int i = 1 ; i <= 4; i++)
{
Console.Write("{0,2} ", i);
}

Console.WriteLine();

for (int i = 12; i <= 14; i++)
{
Console.Write("{0,2} ", i);
}

Console.WriteLine(" 5");
Console.Write("11 ");

for (int i = 16; i >= 15; i--)
{
Console.Write("{0,2} ", i);
}

Console.WriteLine(" 6");

for (int i = 10; i >= 7; i--)
{
Console.Write("{0,2} ", i);
}

Console.ReadKey();
}
}
Vulpes11y ago
Here's some more general code for drawing a spiral like the one you posted except that the number of rows and columns can vary:

using System;

class Spiral
{
static void Main()
{
Console.Write("Enter no of rows : ");
int rows = int.Parse(Console.ReadLine());
Console.Write("Enter no of columns : ");
int cols = int.Parse(Console.ReadLine());
Console.WriteLine();
int[,] matrix = new int[rows, cols];
FillMatrix(matrix, 1, 0);
PrintMatrix(matrix);
Console.ReadKey();
}

static void FillMatrix(int[,] matrix, int startNum, int startRow)
{
int rows = matrix.GetLength(0);
int cols = matrix.GetLength(1);
int maxNum = rows * cols;
int startCol = startRow;

for(int i = startCol; i < cols - startCol; i++)
{
matrix[startRow, i] = startNum++;
}

if (startNum > maxNum) return;

for(int j = startRow + 1; j < rows - startRow; j++)
{
matrix[j, cols - startCol - 1] = startNum++;
}

if (startNum > maxNum) return;

for(int j = cols - startCol - 2; j >= startCol; j--)
{
matrix[rows - startRow - 1, j] = startNum++;
}

for(int j = rows - startRow - 2; j >= startRow + 1; j--)
{
matrix[j, startCol] = startNum++;
}

if (startNum <= maxNum) FillMatrix(matrix, startNum, ++startRow);
}

static void PrintMatrix(int[,] matrix)
{
int rows = matrix.GetLength(0);
int cols = matrix.GetLength(1);

for(int i = 0; i < rows; i++)
{
for(int j = 0; j < cols; j++)
{
Console.Write("{0, 4}", matrix[i, j]);
}

Console.WriteLine();
}
}
}
Nanhe Siddique11y ago
using System;

public class MatrixSpiral
{
    static void Main()
    {
        Console.Write("N = ");
        int n = int.Parse(Console.ReadLine());
        int[,] matrix = new int[n, n];

        FillMatrix(matrix, n);

        PrintMatrix(matrix, n);
    }

    private static void FillMatrix(int[,] matrix, int n)
    {
        int positionX = n / 2; // The middle of the matrix
        int positionY = n % 2 == 0 ? (n / 2) - 1 : (n / 2);

        int direction = 0; // The initial direction is "down"
        int stepsCount = 1; // Perform 1 step in current direction
        int stepPosition = 0; // 0 steps already performed
        int stepChange = 0; // Steps count changes after 2 steps

        for (int i = 0; i < n * n; i++)
        {
            // Fill the current cell with the current value
            matrix[positionY, positionX] = i;

            // Check for direction / step changes
            if (stepPosition < stepsCount)
            {
                stepPosition++;
            }
            else
            {
                stepPosition = 1;
                if (stepChange == 1)
                {
                    stepsCount++;
                }
                stepChange = (stepChange + 1) % 2;
                direction = (direction + 1) % 4;
            }

            // Move to the next cell in the current direction
            switch (direction)
            {
                case 0:
                    positionY++;
                    break;
                case 1:
                    positionX--;
                    break;
                case 2:
                    positionY--;
                    break;
                case 3:
                    positionX++;
                    break;
            }
        }
    }

    private static void PrintMatrix(int[,] matrix, int n)
    {
        for (int i = 0; i < n; i++)
        {
            for (int j = 0; j < n; j++)
            {
                Console.Write("{0,3}", matrix[i, j]);
            }
            Console.WriteLine();
        }
    }
}