I have 3 arrays: x, y and z. How can I write all three to one in one-after-one mode?
For example: I have X=1,2 Y=3,4 Z=5,6
I need an array W = X[1],Y[1],Z[1],X[2],Y[2],Z[2] ... X[n],Y[n],Z[n]
float[] posX = new float[rmv2.lod[0].VerticesCount[0]];
float[] posY = new float[rmv2.lod[0].VerticesCount[0]];
float[] posZ = new float[rmv2.lod[0].VerticesCount[0]];
for (int i = 0; i < 1; i += 3)
{
posX[i] = rmv2.lod[0].Mesh[0].Vertex[i].X;
posY[i + 1] = rmv2.lod[0].Mesh[0].Vertex[i].Y;
posZ[i + 2] = rmv2.lod[0].Mesh[0].Vertex[i].Z;
}
I don't see the w array you're trying to write the output to. Are you looking for something like this?
int n = rmv2.lod[0].VerticesCount[0];
float[] posX = new float[n];
float[] posY = new float[n];
float[] posZ = new float[n];
float[] w = new float[n * 3];
for (int i = 0; i < n; i++)
{
posX[i] = rmv2.lod[0].Mesh[0].Vertex[i].X;
posY[i] = rmv2.lod[0].Mesh[0].Vertex[i].Y;
posZ[i] = rmv2.lod[0].Mesh[0].Vertex[i].Z;
w[i * 3 + 0] = rmv2.lod[0].Mesh[0].Vertex[i].X;
w[i * 3 + 1] = rmv2.lod[0].Mesh[0].Vertex[i].Y;
w[i * 3 + 2] = rmv2.lod[0].Mesh[0].Vertex[i].Z;
}
Perhaps you should look at jagged arrays...
https://msdn.microsoft.com/en-us/library/2s05feca.aspx
Try this:
float[] x = new float[] { 1, 2, 9 };
float[] y = new float[] { 3, 4 };
float[] z = new float[] { 5, 6 };
int max = Math.Max(x.Length, Math.Max(y.Length, z.Length));
List<float> combined = new List<float>();
for (int i = 0; i < max; i++)
{
if (x.Length > i) combined.Add(x[i]);
if (y.Length > i) combined.Add(y[i]);
if (z.Length > i) combined.Add(z[i]);
}
Produces a list with the combined arrays, regardless of their original lengths.
1, 3, 5, 2, 4, 6, 9
If I right understand you, try this solution. With this method arrays can have different length
static T[] ConcatOneAfterOne<T>(params T[][] arrays)
{
int outputArrayLength = 0;
for (int i = 0; i < arrays.Length; i++)
{
outputArrayLength += arrays[i].Length;
}
T[] output = new T[outputArrayLength];
int outputIndex = 0;
int sourceIndex = 0;
while (outputIndex != outputArrayLength)
{
for (int arrayIndex = 0; arrayIndex < arrays.Length; arrayIndex++)
{
if (sourceIndex < arrays[arrayIndex].Length)
{
output[outputIndex++] = arrays[arrayIndex][sourceIndex];
}
}
sourceIndex++;
}
return output;
}
[Test]
static void ConcatOneAfterOneTest()
{
int[] result = ConcatOneAfterOne(new[] { 1, 2 }, new[] { 3, 4 }, new[] { 5, 6 });
CollectionAssert.AreEqual(new int[] { 1, 3, 5, 2, 4, 6 }, result);
}
Related
Is there a efficient way to join blocks in the arrays, as shown here:
original_array = [[1,2], [4,7], [8,10], [15,20], [21,25]]
new_array = [[1,2], [4,10], [15,25]]
Basically I want to join 2 indexes of an array if the distance between them is 1.
I tried something like this but it didin't work.
int[,] new_array = new int[500, 2];
int new_var = 0;
for (int k = 0; k < original_indexes; k++)
{
int dista = original_array [k + 1, 0] - original_array [k, 1];
if (dista < 10)
{
new_array[k, 0] = original_array[k, 0];
new_array[k, 1] = original_array[k + 1, 1];
new_var++;
}
else
{
new_array[k, 0] = original_array[k + new_var, 0];
new_array[k, 1] = original_array[k + new_var, 1];
}
}
Sorry, but I don't know how to be more specific and I don't even know how to search for this.
You can try something like this:
using System.Linq;
...
private static int[,] MyCombine(int[,] source) {
List<int[]> list = new List<int[]>();
int[] last = null;
for (int r = 0; r < source.GetLength(0); ++r)
if (last == null || last[1] + 1 < source[r, 0]) {
if (last != null)
list.Add(last);
last = new int[] { source[r, 0], source[r, 1] };
}
else
last[1] = source[r, 1];
if (last != null)
list.Add(last);
int[,] result = new int[list.Count, 2];
for (int r = 0; r < list.Count; ++r)
for (int c = 0; c < list[r].Length; ++c)
result[r, c] = list[r][c];
return result;
}
Demo:
int[,] original = new int[,] {
{ 1, 2 },
{ 4, 7 },
{ 8, 10 },
{15, 20 },
{21, 25 },
};
int[,] result = MyCombine(original);
string report = "[" + string.Join(", ", Enumerable
.Range(0, result.GetLength(0))
.Select(r => $"[{result[r, 0]}, {result[r, 1]}]")) + "]";
Console.Write(report);
Outcome:
[[1, 2], [4, 10], [15, 25]]
I'm trying to change values between two arrays, but im not getting get that right.
This is what I've done so far
I cant show the total of the first array and i cant make any swap at the second array
public static void exe4()
{
int[,] matriz1 = new int[,] { { -2, 3, 4, 11, -8 }, { -1, 0, -12, -6, 9 }, { 23, 4, 6, 8, -3 } };
int[,] matriz2 = new int[,] { { 2, 3, 8 }, { -2, -4, -5 }, { 0, 8, -14 }, { 3, 5, 6 }, { -9, -8, -1 } };
int troca1 = 0;
int troca2 = 0;
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
troca1 = matriz1[i, j];
matriz1[1, 0] = matriz2[0, 2];
matriz1[1, 1] = matriz2[1, 2];
matriz1[1, 4] = matriz2[4, 1];
}
Console.WriteLine();
}
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
troca2 = matriz2[i, j];
matriz2[0, 2] = matriz1[1, 0];
matriz2[1, 2] = matriz1[1, 1];
matriz2[4, 2] = matriz1[1, 4];
}
Console.WriteLine();
}
Console.WriteLine("\nApós a troca dos valores:\n");
Console.WriteLine("Matriz1:\n");
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
Console.Write("{0}\t", matriz1[i, j]);
}
Console.WriteLine();
}
Console.WriteLine("\nMatriz2:\n");
Console.WriteLine();
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
Console.Write("{0}\t", matriz2[i, j]);
}
Console.WriteLine();
}
That's how it's supposed to be:
Analyzing your solution
It sounds like you're only interested in swapping very few and specific values in those matrices, so for-loops seem unnecessary as you already know the positions in the matrices you want to swap.
Apart from that I noticed that your for-loops only goes from 0 to 2 (for (int i = 0; i < 3; i++)) but your matrices have a length of 4 in one dimension, so the loops never reach the ends.
An alternative solution
If you just want to swap those specific values, you could do it like this:
int[,] matriz1 = new int[,]
{
{ -2, 3, 4, 11, -8 },
{ -1, 0, -12, -6, 9 },
{ 23, 4, 6, 8, -3 }
};
int[,] matriz2 = new int[,]
{
{ 2, 3, 8 },
{ -2, -4, -5 },
{ 0, 8, -14 },
{ 3, 5, 6 },
{ -9, -8, -1 }
};
int temporary;
// Swap A[1,0] with B[0,2]
temporary = matriz1[1,0];
matriz1[1,0] = matriz2[0,2];
matriz2[0,2] = temporary;
// Swap A[1,1] with B[1,2]
temporary = matriz1[1,0];
matriz1[1,1] = matriz2[1,2];
matriz2[1,2] = temporary;
// Swap A[1,4] with B[4,2]
temporary = matriz1[1,0];
matriz1[1,4] = matriz2[4,2];
matriz2[4,2] = temporary;
... or with a little helper function:
void Swap(int[,] matrixA, int row1, int col1, int[,] matrixB, int row2, int col2)
{
var temp = matrixA[row1, col1];
matrixA[row1, col1] = matrixB[row2, col2];
matrixB[row2, col2] = temp;
}
// ...
Swap(matriz1, 1, 0, matriz2, 0, 2);
Swap(matriz1, 1, 1, matriz2, 1, 2);
Swap(matriz1, 1, 4, matriz2, 4, 2);
I am learning C#, and I am doing Multidimensional Arrays at the moment. I want to write a program that reads a matrix and then finds the biggest sum of 2x2 submatrix and prints it.
int[] dimensions = Console.ReadLine()
.Split(", ", StringSplitOptions.RemoveEmptyEntries)
.Select(int.Parse)
.ToArray();
int rows = dimensions[0];
int columns = dimensions[1];
int[,] matrix = new int[rows,columns];
for (int i = 0; i < rows; i++)
{
int[] numbers = Console.ReadLine()
.Split(", ", StringSplitOptions.RemoveEmptyEntries)
.Select(int.Parse)
.ToArray();
for (int j = 0; j < columns; j++)
{
matrix[i, j] = numbers[j];
}
}
int maxSum = int.MinValue;
int selectedRow = -1;
int selectedCol = -1;
for (int row = 0; row < matrix.GetLength(0) - 1; row++)
{
for (int col = 0; col < matrix.GetLength(1) - 1; col++)
{
int currentSum = matrix[row, col] + matrix[row, col + 1] + matrix[row + 1, col] + matrix[row + 1, col + 1];
if (currentSum > maxSum)
{
maxSum = currentSum;
selectedRow = row;
selectedCol = col;
}
}
}
Console.WriteLine($"{matrix[selectedRow, selectedCol]} {matrix[selectedRow, selectedCol + 1]}");
Console.WriteLine($"{matrix[selectedRow + 1, selectedCol]} {matrix[selectedRow + 1, selectedCol + 1]}");
Console.WriteLine(maxSum);
So, I read the matrix, but I am not sure how to start finding the submatrices and compare their sums. I would be very grateful if you could give me some hints.
You need to check values only current, under positions of your i and current, right positions of your j.
I mean it will check like this:
[7,1] [1,3] [3,3]
[1,3] [3,9] [9,8]
And so on.
After every compare, calculate sum of this 2x2 matrix and save it to dictionary.
For return, you just need to find the max value of key and get value of it key.
public class MatrixTest
{
public static IEnumerable<object[]> TestData =>
new List<object[]>
{
new object[]
{
new int[,]
{
{7, 1, 3, 3, 2, 1},
{1, 3, 9, 8, 5, 6},
{4, 6, 7, 9, 1, 0}
},
new int[,]
{
{9, 8},
{7, 9}
},
33
},
new object[]
{
new int[,]
{
{10, 11, 12, 13},
{14, 15, 16, 17}
},
new int[,]
{
{12, 13},
{16, 17}
},
58
}
};
[Theory]
[MemberData(nameof(TestData))]
public void Test(int[,] input, int[,] expectedArray, int expectedSum)
{
MatrixHandler m = new MatrixHandler();
var resp = m.GetMax2x2Matrix(input);
resp.Item1.Should().Be(expectedSum);
resp.Item2.Should().BeEquivalentTo(expectedArray);
}
}
public class MatrixHandler
{
public (int, int[,]) GetMax2x2Matrix(int[,] source)
{
var sumsPlusTempArrays = new Dictionary<int, int[,]>();
int[,] temp;
int sum = 0;
for (int i = 0, n0 = source.GetLength(0) - 1; i <= n0; i++)
{
for (int j = 0, n1 = source.GetLength(1) - 1; j <= n1; j++)
{
if (i + 1 <= n0 && j + 1 <= n1)
{
temp = new int[2,2];
temp[0, 0] = source[i, j];
temp[0, 1] = source[i, j + 1];
temp[1, 0] = source[i + 1, j];
temp[1, 1] = source[i + 1, j + 1];
sum = CalculateSum(temp);
sumsPlusTempArrays.TryAdd(sum, temp);
}
}
}
var key = sumsPlusTempArrays.Select(x => x.Key).Max();
var value = sumsPlusTempArrays[key];
return (key, value);
}
private int CalculateSum(int[,] source)
{
int sum = 0;
for (int i = 0, n0 = source.GetLength(0); i < n0; i++)
{
for (int j = 0, n1 = source.GetLength(1); j < n1; j++)
{
sum += source[i, j];
}
}
return sum;
}
}
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();
}
I want to speed my code up. I'd like that snippet to work faster. I tried to create my own Parallel.For implementation of the loop, but I failed. No errors, but tifDS seems to be empty:/ Could any1 help me? Thanks in advance!
Original loops:
for (int iY = 0; iY < srcDS.RasterYSize; iY++)
{
byte[] srcData = new byte[srcDS.RasterXSize * 1];
srcBand.ReadRaster(0, iY, srcDS.RasterXSize, 1, srcData, srcDS.RasterXSize, 1, 0, 0);
for (int iBand = 0; iBand < _outBands; iBand++)
{
int[] bandLookup = lookup[iBand];
int[] dstData = new int[srcData.Count()];
for (int index = 0; index < srcData.Count(); index++)
{
byte b = srcData[index];
dstData[index] = bandLookup[b];
}
tifDS.GetRasterBand(iBand + 1).WriteRaster(0, iY, srcDS.RasterXSize, 1, dstData,
srcDS.RasterXSize, 1, 0, 0);
}
}
My tries:
for (int iY = 0; iY < srcDS.RasterYSize; iY++)
{
byte[] srcData = new byte[srcDS.RasterXSize * 1];
srcBand.ReadRaster(0, iY, srcDS.RasterXSize, 1, srcData, srcDS.RasterXSize, 1, 0, 0);
Parallel.For<object>((long) 0, _outBands, () => 0,
(iBand, state, subtotal) =>
{
int[] bandLookup = lookup[iBand];
int[] dstData = new int[srcData.Count()];
for (int index = 0; index < srcData.Count(); index++)
{
byte b = srcData[index];
dstData[index] = bandLookup[b];
}
return new object[] {iBand, dstData};
},
o =>
{
int iBand = (int) (o as object[])[0];
int[] dstData = (o as object[])[1] as int[];
lock (_getRasterBandLock)
{
tifDS.GetRasterBand(iBand + 1).WriteRaster(0, iY, srcDS.RasterXSize, 1, dstData,
srcDS.RasterXSize, 1, 0, 0);
}
});
}