I am trying to make a matrix addition program through multithreading, in which i have to divide the rows of both matrices and run them in a separate thread, after that combine all the threads to get the final addition matrix.
i have made the program through single thread but unable to get that done with multiple threads.
this code is for addition with single thread
class Program
{
static void matrixAdd()
{
int[,] a = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 } };
int[,] b = { { 4, 8, 7 }, { 6, 5, 4 }, { 3, 2, 1 } };
int[,] c = new int[3, 3];
int f = c.Length;
int i, m = 0;
int j = 0;
int n = 0;
for (i = 0; i < 3; i++)
{
Console.WriteLine(" ");
for (j = 0; j < 3; j++)
{
Console.Write(" " + a[i, j]);
}
}
Console.Write("\n");
for (m = 0; m < 3; m++)
{
Console.WriteLine(" ");
for (n = 0; n < 3; n++)
{
Console.Write(" " + b[m, n]);
}
}
Console.Write("\n");
for (int k = 0; k < 3; k++)
{
Console.WriteLine("");
for (int l = 0; l < 3; l++)
{
Console.Write(a[k, l] + b[k, l] + "\t");
}
}
}
static void Main(string[] args)
{
Thread t1 = new Thread(matrixAdd);
t1.Start();
Console.ReadLine();
}
Related
So, I needed to find all the index of elements from an array whose sum is equal to N.
For example : Here I want to find indexes whose sum should be equal to 10.
Input : int[] arr = { 2, 3, 0, 5, 7 }
Output: 0,1,3
If you add indexes arr[0] + arr[1] + arr[3] then 2 + 3 + 5 = 10.
I have tried this, but I am running 3 for loops and 3 if conditions, Can we write this in less code, I want to reduce code complexity.
PS: Post suggestions, not codes..
public static void Check1()
{
int[] arr = { 2, 3, 0, 5, 7 };
int target = 10; int total = 0;
bool found = false;
List<int> lst = new List<int>();
for (int i = 0; i < arr.Length; i++)
{
if (!found)
{
for (int j = i + 1; j < arr.Length; j++)
{
if (!found)
{
total = arr[j] + arr[i];
for (int k = j + 1; k < arr.Length; k++)
{
if (total + arr[k] == target)
{
found = true;
Console.WriteLine($"{i}, {i + 1}, {k}");
break;
}
}
}
}
}
}
Console.ReadLine();
}
The Array example is {4, 5, 3, 6, 1}
The user will input the index number and the array will be rotated left from the given index number.
Example: If the user input(index number) is 2, the result is: 3 6 1 4 5.
Any better approach?
public static void Main(string[] args)
{
int[] a = { 4, 2, 8, 3, 1 };
int l = a.Length;
int[] b = new int[l];
int x = 0;
x = Convert.ToInt32(Console.ReadLine());
int i = 0;
for (int j = x; j < l; j++)
{
b[i] = a[j];
i++;
}
for (int k = 0; k < x; k++)
{
int v = a[k];
b[i] = a[k];
i++;
}
for (int m = 0; m < b.Length; m++)
{
Console.Write("{0}, ", b[m]);
}
Console.ReadKey();
}
I will use this method
public static int[] CircularShiftLeft(int[] arr, int shifts)
{
var dest = new int[arr.Length];
Array.Copy(arr, shifts, dest, 0, arr.Length - shifts);
Array.Copy(arr, 0, dest, arr.Length - shifts, shifts);
return dest;
}
Usage in your code, i didnt changed the naming
public static void Main(string[] args)
{
int[] a = { 4, 2, 8, 3, 1 };
int x = 0;
x = Convert.ToInt32(Console.ReadLine());
var b = ShiftLeft(a, x);
for (int m = 0; m < b.Length; m++)
{
Console.Write("{0}, ", b[m]);
}
Console.ReadKey();
}
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();
}
}
}
The task:
1. Make a matrix n by m and fill it with data from console.
2. Find the 3*3 sub matrix with the greatest sum.
{
static int[,] ArrayReadConsole()
{
Console.WriteLine("please enter n:");
int n;
n = Int32.Parse(Console.ReadLine());
Console.WriteLine("please enter m:");
int m;
m = Int32.Parse(Console.ReadLine());
int[,] data = new int[n, m];
for (int i = 0; i < n; i++)
{
for (int j = 0; j < m; j++)
{
Console.WriteLine("please enter a new value");
int number;
number = Int32.Parse(Console.ReadLine());
data[i, j] = number;
}
}
return data;
}
static void SumOfPlatform(int[,] data)
{
int sum =0;
int x = 0;
int y = 0;
int maxSum = 0;
for (int i = 0; i < data.GetLength(0) - 2; i++)
{
for (int j = 0; j < data.GetLength(1) - 2; j++)
{
for (int k = 0; k < 3; k++)
{
for (int l = 0; l < 3; l++)
{
sum =+ data[i + k, j + l];
}
}
if (maxSum < sum)
{
maxSum = sum;
x = i;
y = j;
}
sum =0;
}
}
Console.WriteLine("Sum: {0}\nPosition: {1} {2}",maxSum,x,y );
}
static void Main()
{
int[,] data = ArrayReadConsole();
SumOfPlatform(data);
}
}
}
I wrote that code but something went wrong... It doesn't find position or sum of the matrix I enter. I know that 4x for loop is a bad idea just I didn't want to make another method just for that. Any idea why it doesn't work?
Your Code for SumOfPlatform is working with only change from =+ to +=
static void SumOfPlatform(int[,] data)
{
int sum = 0;
int x = 0;
int y = 0;
int maxSum = 0;
for (int i = 0; i < data.GetLength(0) - 2; i++)
{
for (int j = 0; j < data.GetLength(1) - 2; j++)
{
for (int k = 0; k < 3; k++)
{
for (int l = 0; l < 3; l++)
{
sum += data[i + k, j + l]; //only Change
}
}
if (maxSum < sum)
{
maxSum = sum;
x = i;
y = j;
}
sum = 0;
}
}
Console.WriteLine("Sum: {0}\nPosition: {1} {2}", maxSum, x, y);
}
static void Main(string[] args)
{
// int[,] data = ArrayReadConsole();
int[,] data = new int[,]
{
{1,4,6,7,3,5,7,4 },
{1,4,5,3,3,5,4,4 },
{1,1,6,2,1,5,7,4 },
{1,3,6,3,3,5,2,4 },
{1,4,6,2,3,5,3,4 },
{1,4,2,2,3,5,3,4 },
{1,4,3,3,3,5,2,4 },
{1,4,4,3,3,5,2,4 }
};
SumOfPlatform(data);
}
I am just sorting an array and my code seem to be fine but I am unable to resolve the Array Out of Bound Exception. Any ideas.
static void Main(string[] args)
{
int temp = 0; // For temporary holding array values for swapping
int [] num = new int[] {1, 4, 7, 6, 9, 3, 0, 8, 5, 2 };
for (int i = 0; i <= 9; i++) //Outer loop
{
for (int j = 0; j < 9; j++) // Inner loop
{
if (num[j] > num[j + 1])
{
temp = num[j + 1];
num[j + 1] = num[j];
num[j] = temp;
}
}
}
//Displaying the array
for (int i = 0; i < 9; i++)
Console.WriteLine(num[i]);
Console.ReadKey();
}
Modifying the second loop to "j < loopSize - i" (instead of j < loopSize) will double the efficiency of your bubble sort. :)
int[] num = new int[] { 1, 4, 7, 6, 9, 3, 0, 8, 5, 2 };
//int comparisons = 0;
int loopSize = num.Length - 1;
for (int i = 0; i <= loopSize; i++) //Outer loop
{
for (int j = 0; j < loopSize - i; j++) // Inner loop
{
//comparisons++;
if (num[j] > num[j + 1])
{
temp = num[j + 1];
num[j + 1] = num[j];
num[j] = temp;
}
}
}
//Displaying the array
for (int i = 0; i < num.Length; i++)
Console.WriteLine(num[i]);
//Console.WriteLine("comp: {0}", comparisons);
//Console.ReadKey();
}