I have a 10x10 matrix that I am filling with random chars. My problem is that I can't figure out how to insert a string "HOUSE" into the first row of the table.
Random rchar = new Random();
string word = "HOUSE";
char[] wordChars = word.ToCharArray();
char[,] arr = new char[10, 10];
//Size of Rows and Cols
var rowLength = arr.GetLength(0);
var colLength = arr.GetLength(1);
for (int x = 0; x < rowLength; x++)
{
for (int y = 0; y < colLength; y++)
{
arr[0, y] = wordChars[1];
arr[x, y] = (char)(rchar.Next(65, 91));
Console.Write(arr[x, y] + " ");
}
Console.WriteLine();
}
I was trying to place a new value with the SetValue property but it doesn't work for me because I have a two-dimensional array.
Just set to your arr using two dimentional indices like [1,1] or [x,y]
Example:
public static void Main()
{
Random rchar = new Random();
char[,] arr = new char[10, 10];
//Size of Rows and Cols
var rowLength = arr.GetLength(0);
var colLength = arr.GetLength(1);
for (int x = 0; x < rowLength; x++)
{
for (int y = 0; y < colLength; y++)
{
arr[x,y] = (char)(rchar.Next(65, 91));
Console.Write(arr[x, y] + " ");
}
Console.WriteLine();
}
}
Try running this piece of code, I think it covers your question of setting values in a multidimensional array.
Also I see a "chars[1]" in your code, this variable does not exist, did you mean to get the random char here?
You might want to look up how to get a random char and put it in that spot.
char[,] arr = new char[10, 10];
arr[0, 0] = 'a';
arr[0, 1] = 'b';
arr[0, 2] = 'c';
arr[1, 0] = 'd';
arr[1, 1] = 'e';
arr[1, 2] = 'f';
for (int i = 0; i < 3; i++)
{
Console.WriteLine(arr[0, i]);
}
for (int i = 0; i < 3; i++)
{
Console.WriteLine(arr[1, i]);
}
Related
How can I bubble sort a 2D string array by their lenght? In the array's zeroth column there are random generated messages and in the first column there are random generated priorities.
string[,] array = new string[50, 2];
Random r = new Random();
int number = 0;
int space = 0;
double fontossag = 0;
for (int i = 0; i < 50; i++)
{
string message = "";
int hossz = r.Next(10,51);
for (int h = 0; h < hossz; h++)
{
number = r.Next(0,101);
space = r.Next(0, 101);
if (number<=50)
{
message += (char)r.Next(97,122);
}
else if(number >= 50)
{
message += (char)r.Next(65, 90);
}
if (space<=10)
{
message += " ";
}
}
for (int f = 0; f < 50; f++)
{
fontossag = r.NextDouble() * (10.0);
}
array[i, 0] += message;
array[i, 1] += fontossag;
}
I want to sort the array by the random generated messages length.
This is my method to Bubble sort on the first column length:
public static string[,] BubbleSortStringByLength(string[,] array)
{
int num = array.GetLength(0);
for (int i = 0; i < num - 1; i++)
{
for (int j = 0; j < num - i - 1; j++)
{
if (array[j, 0].Length > array[j + 1, 0].Length)
{
// swap first column
string tmp = array[j, 0];
array[j, 0] = array[j + 1, 0];
array[j + 1, 0] = tmp;
// swap second column
tmp = array[j, 1];
array[j, 1] = array[j + 1, 1];
array[j + 1, 1] = tmp;
}
}
}
return array;
}
You can download the Visual Studio solution on GitHub
So you want to compare lengths of 1st columns and swap rows to ensure descending priority:
for (bool hasWork = true; hasWork;) {
hasWork = false;
for (int row = 0; row < array.GetLength(0) - 1; ++row) {
int priority1 = array[row, 0]?.Length ?? -1;
int priority2 = array[row + 1, 0]?.Length ?? -1;
// if we have wrong order...
if (priority1 < priority2) {
// we should keep on working to sort the array
hasWork = true;
// and swap incorrect rows
for (int column = 0; column < array.GetLength(1); ++column)
(array[row, column], array[row + 1, column]) =
(array[row + 1, column], array[row, column]);
}
}
}
Please, fiddle yourself
I want to randomly generate two matrix arrays so I can later add them up and store them into a third matrix, how would I go about doing this? Nearly totally lost, here's what I have so far.
using System;
namespace question2_addingrandommatrice
{
class Program
{
static void Main(string[] args)
{
Random random = new Random();
int[,] newarray = new int[3, 3];
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
int ran2 = random.Next(-10, 10);
int ran1 = random.Next(-10, 10);
newarray[i, j] = ran1, ran2;
}
}
Console.ReadKey();
}
}
}
You are nearly there, you just needed one random.Next
Here is a method that does it for you
private static int[,] GenerateRandomMatrix(int x, int y)
{
var array = new int[x, y];
for (int i = 0; i < array.GetLength(0); i++)
for (int j = 0; j < array.GetLength(1); j++)
array[i, j] = random.Next(-10, 10);
return array;
}
Add pepper and salt to taste
Usage
// 3*3 random matrix
var matrix = GenerateRandomMatrix(3,3);
Additional Resources
Multidimensional Arrays (C# Programming Guide)
You can simply do this.
Random random = new Random();
int[,] newarray = new int[3, 3];
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
newarray[i, j] = random.Next(-10, 10); ;
}
I am practicing with 2D arrays and am making a program that separates a 2D array with random integer values into two separate arrays based on if the values are even or odd.
However, the program seems to be adding additional zeroes to each row in the even and odd arrays. What am I doing wrong?
I think the problem is in the sort() function where I determine the size of the even and odd arrays but I am not sure.
class Program
{
static void Main(string[] args)
{
int[,] arr = new int[10, 10];
// Fills 2D array with random values and prints them out
Random r = new Random();
for (int y = 0; y < arr.GetLength(0); y++)
{
for (int x = 0; x < arr.GetLength(1); x++)
{
arr[y, x] = r.Next(1, 99);
Console.Write(arr[y,x] + " ");
}
Console.WriteLine();
}
Console.WriteLine();
// Function that separates original array into 2 separate ones (even and odd)
sort(arr);
Console.ReadLine();
}
public static void sort(int[,] array)
{
int j1 = 0;
int i1 = 0;
int j2 = 0;
int i2 = 0;
// Increases the size of the even/odd arrays whenever the value of the original array is even/odd respectively
// I think this is where the problem is
for (int y = 0; y < array.GetLength(0); y++)
{
for (int x = 0; x < array.GetLength(1); x++)
{
if (array[y,x] % 2 == 0)
{
i1 += 1;
}
else
{
i2 += 1;
}
}
j1 += 1;
j2 += 1;
}
int[,] evenArr = new int[j1, i1];
int[,] oddArr = new int[j2, i2];
// Sets the values for the even/odd arrays
for (int y = 0; y < array.GetLength(0); y++)
{
for (int x = 0; x < array.GetLength(1); x++)
{
if (array[y, x] % 2 == 0)
{
evenArr[y, x] = array[y, x];
}
else
{
oddArr[y, x] = array[y, x];
}
}
}
// Prints the values for the even array
for (int y = 0; y < evenArr.GetLength(0); y++)
{
for (int x = 0; x < evenArr.GetLength(1); x++)
{
Console.Write(evenArr[y, x] + " ");
}
Console.WriteLine();
}
Console.WriteLine();
// Prints the values for the odd array
for (int y = 0; y < oddArr.GetLength(0); y++)
{
for (int x = 0; x < oddArr.GetLength(1); x++)
{
Console.Write(oddArr[y, x] + " ");
}
Console.WriteLine();
}
}
}
When you initialize your arrays (evenArr = new int[j1, i1], oddArr = new int[j2, i2];) the default values are zero. Since there's an extra zero it means you should check the length and probably reduce it by one.
If matrix A of size (3x3), then should i use the method of finding determinants, like grabbing the rows and column of first element and removing it from the array 2D array to get the remaining elements and then moving to the next element and repeating the same steps ?
[{1,2,3},
{4,5,6},
{7,8,9}]
I finally was able to do it, here's what I did :
enter image description here
class program
{
public static void Main()
{
int[,] arr = new int[3, 3];
Console.WriteLine("Enter elements of " + (arr.GetUpperBound(0) + 1) + "x" + (arr.GetUpperBound(1) + 1) + " matrix:");
for (int i = 0; i < (arr.GetUpperBound(0) + 1); i++)
{
for (int j = 0; j < (arr.GetUpperBound(1) + 1); j++)
{
arr[i, j] = Convert.ToInt32(Console.ReadLine());
}
}
Console.WriteLine("Matrix entered: ");
for (int i = 0; i < (arr.GetUpperBound(0) + 1); i++)
{
for (int j = 0; j < (arr.GetUpperBound(1) + 1); j++)
{
Console.Write("\t" + arr[i, j]);
}
Console.WriteLine();
}
Console.WriteLine("Possible sub-matrices: ");
for (int i = 0; i < 3; i++)
{
for (int j = 0; j< 3; j++)
{
TrimArray(i,j,arr);
}
}
}
public static int[,] TrimArray(int row, int column, int[,] original)
{
int[,] resultant = new int[original.GetLength(0) - 1, original.GetLength(1) - 1];
for (int i = 0, j = 0; i < original.GetLength(0); i++)
{
if (i == row)
continue;
for (int k = 0, u = 0; k < original.GetLength(1); k++)
{
if (k == column)
continue;
resultant[j, u] = original[i, k];
u++;
}
j++;
}
Console.WriteLine();
for (int i = 0; i < 2; i++)
{
for (int j = 0; j< 2; j++)
{
Console.Write("\t"+resultant[i,j]);
}
Console.WriteLine();
}
return resultant;
}
}
I did this for you yesterday, I created a method that will return a square matrix, given a parent matrix and the length.
static void Main(string[] args)
{
int[][] parentMatrix = new int[][]
{
new int [] { 1, 2, 3 },
new int [] { 4, 5, 6 },
new int [] { 7, 8, 9 }
};
var chunks = GetSubMatrices(parentMatrix, 2);
Console.WriteLine(chunks);
}
static List<int[][]> GetSubMatrices(int[][] parentMatrix, int m)
{
int n = parentMatrix.Length > m ? parentMatrix.Length : throw new InvalidOperationException("You can't use a matrix smaller than the chunk size");
var chunks = new List<int[][]>();
int movLimit = n - m + 1;
var allCount = Math.Pow(movLimit, 2);
for (int selRow = 0; selRow < movLimit; selRow ++)
{
for (int selCol = 0; selCol < movLimit; selCol ++)
{
// this is start position of the chunk
var chunk = new int[m][];
for (int row = 0; row < m; row++)
{
chunk[row] = new int[m];
for (int col = 0; col < m; col++)
{
chunk[row][col] = parentMatrix[selRow + row][selCol + col];
}
}
chunks.Add(chunk);
}
}
return chunks;
}
If you have any problems using it, you can simply comment below.
I needed to solve a problem like and came up with this answer. Hope it adds to your library of answers. If the submatrix specified is not greater than 1, do nothing.
public static void GetSubMatrixes(int[,] arr, int size)
{
int parentMatrixRowLength = arr.GetLength(0);
int parentMatrixColLength = arr.GetLength(1);
var overall = new List<object>();
if(size > 1)
{
for (int i = 0; i < parentMatrixRowLength; i++)
{
//get the columns
for (int j = 0; j < parentMatrixColLength; j++)
{
var subMatrix = new int[size, size];
/*if the new matrix starts from second to the last value in either the row(horizontal or column)
* do not proceed, go to the row or column in the parent matrix
* */
if (j < parentMatrixColLength - (size - 1) && i < parentMatrixRowLength - (size - 1))
{
//add
for (int m = 0; m < subMatrix.GetLength(0); m++)
{
for (int n = 0; n < subMatrix.GetLength(1); n++)
{
/*check the sum of current column value and the sum of the current row value
* of the parent column length and row length if it goes out of bounds
*/
var row = i + m; var col = j + n;
//actual check here
if (row < parentMatrixRowLength && col < parentMatrixColLength)
{
subMatrix[m, n] = arr[i + m, j + n];
}
}
}
overall.Add(subMatrix);
}
}
}
//display the sub matrixes here
for (int i = 0; i < overall.Count; i++)
{
var matrix = overall[i] as int[,];
for (int y = 0; y < matrix.GetLength(0); y++)
{
for (int x = 0; x < matrix.GetLength(1); x++)
{
Console.Write(string.Format("{0} ", matrix[y, x]));
}
Console.Write(Environment.NewLine + Environment.NewLine);
}
Console.WriteLine();
}
}
}
I am trying to learn two dimensional array and I wrote some basic code, but I am getting this exception. Could you tell me what am I doing wrong?
static void Main(string[] args)
{
Random rnd = new Random();
int[,] array = new int[2, 2];
for (int i = 0; i < 2; i++)
{
for (int j = 0; j < 2; i++)
{
array[i, j] = rnd.Next(0, 100);
}
}
for (int i = 0; i < array.GetLength(0); i++)
{
Console.WriteLine(array[i, 0] + "---" + array[i, 1]);
}
Console.ReadLine();
}
The problem is in your inner for-loop. In the iterator section, you're incrementing the i variable, but it should be j. Try this:
for (int i = 0; i < 2; i++)
{
for (int j = 0; j < 2; j++)
{
array[i, j] = rnd.Next(0, 100);
}
}