I have a program that creates a transpose 5x8 matrix. I have created an multi dimensional 5x8 array and I also created a new array that hold the transpose of the multi dimensional array. The thing is, I first want to write out the original matrix to the console, and on the same line i want the transpose to be written out. Here is my code:
class Program
{
static void Main(string[] args)
{
int[,] matrix = new int[5, 8] {
{ 1, 2, 3, 4, 5,6,7,8 },
{ 9,10,11,12,13,14,15,16},
{ 17,18,19,20,21,22,23,24 },
{ 25,26,27,28,29,30,31,32 },
{ 33,34,35,36,37,38,39,40 },
};
for (int j = 0; j < 8; j++)
{
for (int r = 0; r < 5; r++)
Console.Write("{0} ", matrix[r, j]);
Console.WriteLine();
}
int[,] newArray = new int[8, 5];
for (int j = 0; j < 8; j++)
for (int r = 0; r < 5; r++)
newArray[j, r] = matrix[r, j];
Console.ReadLine();
}
}
what I want is to be shown on the console window is like this:
http://pbrd.co/19SXR0J
but I can only print out the transpose matrix. How do I fix this?
You can just print both lines at a same time, after you computed the transpose.
for (int j = 0; j < 8; j++)
{
//write a line from the first matrix
for (int r = 0; r < 5; r++)
Console.Write("{0} ", matrix[r, j]);
//add some spaces for visual separation
Console.Write("\t\t");
//write a line from the transpose matrix
for (int r = 0; r < 5; r++)
Console.Write("{0} ", newArray[r, j]);
Console.WriteLine();
}
Related
As you can see this is 2D transpose of matrix program, when executing this program it throws an index out of bound exception when it reached in some lines of code. Code raising exception is mentioned below.
C# Program
static void Main(string[] args)
{
Console.Write("No of Rows entered = ");
int r = Convert.ToInt32(Console.ReadLine());
Console.Write("No of Columns entered = ");
int c= Convert.ToInt32(Console.ReadLine());
int[,] arr1 = new int[r, c];
int[,] arr2 = new int[r, c];
for (int i = 0; i < r; i++)
{
for (int j = 0; j < c; j++)
{
Console.Write("[{0}],[{1}] : ", i, j+" ");
arr1[i, j] = Convert.ToInt32(Console.ReadLine());
}
}
Console.WriteLine("Matrix before Transpose:");
for (int i = 0; i < r; i++)
{
Console.WriteLine();
for (int j = 0; j < c; j++)
Console.Write("{0}", arr1[i, j]+" ");
}
```
**When it execute this lines of code it shows exception**
```
for (int i = 0; i < r; i++)
{
for (int j = 0; j < c; j++)
{
arr2[j, i] = arr1[i, j];
}
}
Console.WriteLine("Matrix after Transpose: ");
for (int i = 0; i < r; i++)
{
Console.WriteLine();
for (int j = 0; j < c; j++)
{
Console.Write("{0}", arr2[i, j]);
}
}
}
```
[Image of Exception appear while executing the program][1]
[1]: https://i.stack.imgur.com/6rNCg.png
The position of r and c should be changed in the definition of arr2:
int[,] arr2 = new int[c, r];
In the last for-loop, r and c should also be changed from position:
Console.WriteLine("Matrix after Transpose: ");
for (int i = 0; i < c; i++)
{
Console.WriteLine();
for (int j = 0; j < r; j++)
{
Console.Write("{0}", arr2[i, j]);
}
}
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'm a new student having a bit of trouble with this assignment, but the powerpoint notes and other online guides don't seem to help. If anyone can give me a pointer it would be much appreciated!
private static int[,] GenerateTT(int size)
{
int[,] table = new int[size,size];
for (int i = 1; i < size+1; i++)
{
for (int j = 1; j < i+1; j++)
{
table[i-1, j-1] = i * j;
}
}
return table;
}
private static void DisplayTT(int[,] table)
{
Console.WriteLine();
Console.WriteLine("Here is the times table for that size:");
Console.WriteLine();
for (int i = 1; i <= table.Length; i++)
{
for (int j = 1; j <= i; j++)
{
Console.Write("{0}\t", table[i-1, j-1]);
}
Console.WriteLine("\n");
}
Console.WriteLine();
}
The output is supposed to be like this (if you enter 4 for example):
1 2 3 4
2 4 6 8
3 6 9 12
4 8 12 16
But what I'm getting is this, plus it crashes at DisplayTT(table):
1
2 4
3 6 9
4 8 12 16
here's the relevant part of the Main method if it helps.
int size = GetValue("Please enter the size (4-20) of the times table: ", 4, 20);
Console.WriteLine();
int[,] table = GenerateTT(size);
DisplayTT(table);
You can use GetLength(X) Property for multi dimensional arrays where X is index of dimension.
for (int i = 0; i < table.GetLength(0); i++)
{
for (int j = 0; j < table.GetLength(1); j++)
{
Console.Write("{0}\t", table[i, j]);
}
Console.WriteLine("\n");
}
You should change the inner loop hi-bound:
private static int[,] GenerateTT(int size)
{
int[,] table = new int[size,size];
for (int i = 1; i < size+1; i++)
{
for (int j = 1; j < i+1; j++) // <-- change i+1 to size+1
{
table[i-1, j-1] = i * j;
}
}
return table;
}
I'd rather keep the loops start from zero:
private static int[,] GenerateTT(int size)
{
int[,] table = new int[size,size];
for (int i = 0; i < size; i++)
{
for (int j = 0; j < size; j++)
{
table[i, j] = (i+1) * (j+1);
}
}
return table;
}
The following code sorts rows by the first element using bubble method.
I can't change it to counting sort.
public void SortStack(double[,] n)
{
for (int i = 0; i < n.GetLength(0) - 1; i++)
{
for (int j = i; j < n.GetLength(0); j++)
{
if (n[i, 0] > n[j, 0])
{
for (int k = 0; k < n.GetLength(1); k++)
{
var temp = n[i, k];
n[i, k] = n[j, k];
n[j, k] = temp;
}
}
}
}
}
Please help.
As you do bubble sort based on first element of each row. you should do counting sort like that too. so you just need to count first item of each row.
private static int[,] CountingSort2D(int[,] arr)
{
// find the max number by first item of each row
int max = arr[0, 0];
for (int i = 0; i < arr.GetLength(0); i++)
{
if (arr[i, 0] > max) max = arr[i, 0];
}
// we want to get count of first items of each row. thus we need 1d array.
int[] counts = new int[max + 1];
// do the counting. again on first index of each row
for (int i = 0; i < arr.GetLength(0); i++)
{
counts[arr[i, 0]]++;
}
for (int i = 1; i < counts.Length; i++)
{
counts[i] += counts[i - 1];
}
// result is sorted array
int[,] result = new int[arr.GetLength(0), arr.GetLength(1)];
for (int i = arr.GetLength(0) - 1; i >= 0; i--)
{
counts[arr[i, 0]]--;
// now we need to copy columns too. thus we need another loop
for (int j = 0; j < arr.GetLength(1); j++)
{
result[counts[arr[i, 0]], j] = arr[i, j];
}
}
return result;
}
Here is the test.
static void Main()
{
Random rand = new Random();
int[,] arr = new int[3,3];
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
arr[i, j] = rand.Next(0, 100);
}
}
int[,] newarr = CountingSort2D(arr);
for (int i = 0; i < arr.GetLength(0); i++)
{
Console.Write("{ ");
for (int j = 0; j < arr.GetLength(1); j++)
{
Console.Write(arr[i, j] + " ,");
}
Console.Write("} ,");
}
Console.WriteLine();
for (int i = 0; i < newarr.GetLength(0); i++)
{
Console.Write("{ ");
for (int j = 0; j < newarr.GetLength(1); j++)
{
Console.Write(newarr[i, j] + " ,");
}
Console.Write("} ,");
}
Console.WriteLine();
}
Example Output:
{ 49,66,8 },{ 33,39,64 },{ 65,52,76 } // Original array
{ 33,39,64 },{ 49,66,8 },{ 65,52,76 } // Sorted array
enter code here
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace testing_random
{
class Program
{
static void Main(string[] args)
{
int n = 4;
int[,] a = new int[n,n];//declaring the matrix
Random o = new Random();
a[0,0] = o.Next(n);
for (int i = 1; i < n; i++)//filling the first line
{
int d = 1;
while (d != 0)
{
a[i,0] = o.Next(n);
d = 0;
for (int j = 0; j < i; j++)
if (a[i,0] == a[j,0])
d++;
}
}
for (int i = 1; i < n; i++)//filing the first column
{
int d = 1;
while (d != 0)
{
a[0, i] = o.Next(n);
d = 0;
for (int j = 0; j < i; j++)
if (a[0, i] == a[0, j])
d++;
}
}
for (int k = 1; k < n; k++)//filling the rest of the matrix
for (int i = 1; i < n; i++)
{
int d = 1;
while (d != 0)
{
a[i, k] = o.Next(n);
d = 0;
for (int j = 0; j < i; j++)
if (a[i, k] == a[j, k])
d++;
for (int j = 0; j < k; j++)
if (a[i, k] == a[i, j])
d++;
}
}
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
Console.Write("{0} ", a[i, j]);
Console.WriteLine();
}
Console.ReadLine();
}
}
}
The output should be a matrix of 4*4 where each column and each line contains each number once.
The problem is when i run the code, not every time i get an output, i think the problem is not every set of first line and column can give a matrix as required the i get into an unending loop.
what i want to do is limit the running time of the application to 100 ms per example,so if the matrix is not filled,the program restarts
What piece of code am i missing?
replace the while( d != 0 ) with a loop which counts up to a certain very large maximum number of iterations. (Try 1000, 100000, whatever.)
Are you trying to randomly insert numbers between 1-4 in the first line of the array? If so there is a much easier way to do it.
You can generate the 4 numbers to be inserted into the array and then just look through the first line of the array and set each value.
Random rnd = new Random();
var randomNumbers = Enumerable.Range(1, 4).OrderBy(i => rnd.Next()).ToArray();
for (int i = 0; i < n; i++)
{
a[i, 0] = randomNumbers[i];
}