I have to write a program that creates a two dimensional array and fills it like a snake. Here is the task itself:
Blockquote write a program that creates a two-dimensional numeric array and this array is filled with a "snake": first the first row (from left to right), then the last column (from top to bottom), the last row (from right to left), the first column (from bottom to top), the second row ( left to right), etc.
I tried to write something, but bugs constantly appear. Please help to shorten this code and make it correct.
class Program
{
static void Main(string[] args)
{
Random rand = new Random();
int len = rand.Next(5, 20);
int wid = rand.Next(5, 20);
int[,] arr = new int[len, wid];
int num = 10;
int line = 0;
int line2 = len;
int col = wid - 1;
int col2 = 0;
for (int i = 0; i <= (len > wid ? len : wid); i++)
{
for (int k = 0; k < wid; k++, num++)
{
arr[line, k] = num;
}
line++;
for (int k = 0; k < len; k++, num++)
{
arr[k, col] = num;
}
col++;
for (int k = (wid - 1); k >= 0; k--, num++)
{
arr[line2, k] = num;
}
line2++;
for (int k = 0; k < (len - 1); k++, num++)
{
arr[k, col2] = num;
}
col2++;
}
for (int i = 0; i <= len; i++)
for (int q = 0; q <= wid; q++)
{
Console.WriteLine(arr[i, q] + " ");
}
}
}
Related
Hi i am trying to calculate the sums of the submatrix of order K from a matrix of order M, but I am getting wrong result from the sums matrix. In my head the logic makes sense, I don't know what the mistake is.
static void Main(string[] args)
{
Console.WriteLine("Shkruani te madhesine e matrices dhe madhesine e submatrices: ");
int M;
int K;
int sum = 0;
M = int.Parse(Console.ReadLine());
K = int.Parse(Console.ReadLine());
int[] sums = new int[M - K + 1];
int[] matrix = new int[M];
Console.WriteLine("Shkruani vlerat e matrices: ");
foreach (int i in matrix)
{
matrix[i] = int.Parse(Console.ReadLine());
}
for (int i = 0; i <= M - K; i++)
{
for (int j = 0; j < K; j++)
{
sum += matrix[i + j];
}
sums[i] = sum;
sum = 0;
}
for (int i = 0; i < (M - K + 1); i++)
{
Console.WriteLine(sums[i]);
}
Console.ReadKey();
}
Instead of using
foreach (int i in matrix)
{
matrix[i] = int.Parse(Console.ReadLine());
}
Use this:
for (int i = 0; i < matrix.Length; i++)
{
matrix[i] = int.Parse(Console.ReadLine());
}
Explanation:
Because For-Each loop works with value (iterate through value) instead of index (May be what you want) while for loop works with index (iterate through index).
Hope this helps.
Thank you.
I want to shift elements in one array to right by only changing the index. Also I don't want to use built-in functions
For example, if we have
8,6,5,3,9
Then We will have
9,8,6,5,3
If the array doesn't have enough length. the rest of the elements shift will start from the first index of array.
int index = 0, temp = 0;
int[] myarray = new int[int.Parse(Console.ReadLine())];
for (int i = 0; i < myarray.Length; i++)
{
myarray[i] = int.Parse(Console.ReadLine());
}
for (int i = 0; i < myarray.Length; i++)
{
if (myarray.Length <= i + 5)
{
index = ((i + 5) % 5);
temp = myarray[index];
myarray[index] = myarray[i];
myarray[i] = temp;
}
else
{
temp = myarray[i + 5];
myarray[i + 5] = myarray[i];
myarray[i] = temp;
}
}
this is what i have tried but its not working
If shift count is less than or equal array size you can use this code (I edited answer by this link):
using System;
int M = 5;//shift count
int size; //size of array
int[] myarray = new int[int.Parse(Console.ReadLine())];
for (int i = 0; i < myarray.Length; i++)
{
myarray[i] = int.Parse(Console.ReadLine());
}
size = myarray.Length;
if (size >= M)
{
Array.Reverse(myarray, 0, size);
Array.Reverse(myarray, 0, M);
Array.Reverse(myarray, M, size - M);
for (int i = 0; i < myarray.Length; i++)
{
Console.Write(myarray[i]+"\t");
}
Console.Read();
}
This program generates random 2d array and calculates maximum in every line. I do have right results, but IndexOutOfRangeException popping up if number of columns does not equals to the number of lines.
Random r = new Random();
int x,y;
Console.WriteLine("lines");
x = int.Parse(Console.ReadLine());
Console.WriteLine("columns");
y = int.Parse(Console.ReadLine());
if ((x < 1) || (y < 1))
{
Console.WriteLine("Error");
Console.ReadLine();
}
else
{
int[,] array1 = new int[x, y];
int[] array2 = new int[y];
for (int i = 0; i < x; i++)
{
for (int j = 0; j < y; j++)
{
array1[i, j] = r.Next(0, 51);
Console.Write(array1[i, j] + " ");
}
Console.WriteLine();
}
for (int j = 0; j < y; j++)
{
int max = array1[j, 0];
for (int i = 1; i < x; i++)
{
if (array1[j, i] > max)
{
max = (array1[j, i]);
}
else
{
}
}
array2[j] = max;
Console.WriteLine();
Console.Write(array2[j]);
}
Console.ReadLine();
}
On your second pass through the data (the one where you go by lines first rather than by columns), this:
if (array1[j, i] > max)
{
max = (array1[j, i]);
}
should look like this:
if (array1[i, j] > max)
{
max = (array1[i, j]);
}
Changing the order in which you process rows and columns doesn't change the dimensions of the array.
Edit: per #csharpfolk's comment, this line also needs fixing:
int max = array1[j, 0];
probably to:
int max = array1[0, j];
Below is the code I wrote for clustering using genetic algorithm. Points are from a picturebox, generated randomly (X,Y) before calling this class. However, the result of this algorithm is much worse than k-means or lbg I'm comparing it to. Can someone take a look for any errors in the algorithm, maybe I omitted something. Thanks.
I did this using arrays, the 2 other I did using lists, but I don't think that should have any impact on result.
public class geneticAlgorithm
{
static int pom = 0;
static PictureBox pb1;
public geneticAlgorithm(PictureBox pb)
{
pb1 = pb;
}
public static void doGA(PointCollection points, int clusterCounter)
//points is a list of points,
//those point have (X,Y) coordinates generated randomly from pictureBox
//coordinates. clusterCounter is how many clusters I want to divide the points into
{
//this part converts list of points into array testtab,
//where each array field hold X,Y of a point
Point[] test = new Point[points.Count];
test = points.ToArray();
double[][] testtab = new double[test.Length][];
for (int i = 0; i < testtab.GetLength(0); i++)
{
testtab[i] = new double[2];
testtab[i][0] = test[i].X;
testtab[i][1] = test[i].Y;
}
//end of converting
int n = testtab.GetLength(0);
int k = clusterCounter;
int chromosomeCount = 500;
int dimensions = 2;
double[][] testClusters = new double[k][];
for (int i = 0; i < k; i++)
{
testClusters[i] = new double[dimensions];
}
double[][] testChromosomes = new double[chromosomeCount][];
for (int i = 0; i < chromosomeCount; i++)
{
testChromosomes[i] = new double[2 * k];
}
int[][] testChromosomesInt = new int[chromosomeCount][];
for (int i = 0; i < chromosomeCount; i++)
{
testChromosomesInt[i] = new int[2 * k];
}
double[] partner = new double[chromosomeCount];
double[][] roulette = new double[chromosomeCount][];
for (int i = 0; i < chromosomeCount; i++)
{
roulette[i] = new double[1];
}
double[][] errors = new double[chromosomeCount][];
for (int i = 0; i < chromosomeCount; i++)
{
errors[i] = new double[1];
}
double crossingPossibility = 0.01;
double mutationPossibility = 0.0001;
int maxIterations = 10000;
//here I create chromosomes and initial clusters
for (int j = 0; j < chromosomeCount; j++)
{
for (int i = 0; i < k; i++)
{
Random rnd = new Random();
int r = rnd.Next(n);
for (int q = 0; q < dimensions; q++)
{
testClusters[i][q] = testtab[r][q];
}
}
int help = 0;
for (int i = 0; i < k; i++)
for (int l = 0; l < dimensions; l++) // here is creation of chromosome
{
testChromosomes[j][help] = testClusters[i][l];
help++;
}
//end
//here I call accomodation function to see which of them are good
errors[j][0] = accomodationFunction(testClusters, testtab, n, k);
//end
//cleaning of the cluster table
testClusters = new double[k][];
for (int i = 0; i < k; i++)
{
testClusters[i] = new double[dimensions];
}
}
//end
for (int counter = 0; counter < maxIterations; counter++)
{
//start of the roulette
double s = 0.0;
for (int i = 0; i < chromosomeCount; i++)
s += errors[i][0];
for (int i = 0; i < chromosomeCount; i++)
errors[i][0] = chromosomeCount * errors[i][0] / s;
int idx = 0;
for (int i = 0; i < chromosomeCount; i++)
for (int j = 0; i < errors[i][0] && idx < chromosomeCount; j++)
{
roulette[idx++][0] = i;
}
double[][] newTab = new double[chromosomeCount][];
for (int i = 0; i < chromosomeCount; i++)
{
newTab[i] = new double[2 * k];
}
Random rnd = new Random();
for (int i = 0; i < chromosomeCount; i++)
{
int q = rnd.Next(chromosomeCount);
newTab[i] = testChromosomes[(int)roulette[q][0]];
}
testChromosomes = newTab;
//end of roulette
//start of crossing chromosomes
for (int i = 0; i < chromosomeCount; i++)
partner[i] = (rnd.NextDouble() < crossingPossibility + 1) ? rnd.Next(chromosomeCount) : -1;
for (int i = 0; i < chromosomeCount; i++)
if (partner[i] != -1)
testChromosomes[i] = crossing(testChromosomes[i], testChromosomes[(int)partner[i]], rnd.Next(2 * k), k);
//end of crossing
//converting double to int
for (int i = 0; i < chromosomeCount; i++)
for (int j = 0; j < 2 * k; j++)
testChromosomes[i][j] = (int)Math.Round(testChromosomes[i][j]);
//end of conversion
//start of mutation
for (int i = 0; i < chromosomeCount; i++)
if (rnd.NextDouble() < mutationPossibility + 1)
testChromosomesInt[i] = mutation(testChromosomesInt[i], rnd.Next(k * 2), rnd.Next(10));
//end of mutation
}
//painting of the found centre on the picture box
int centrum = max(errors, chromosomeCount);
Graphics g = pb1.CreateGraphics();
SolidBrush brush = new SolidBrush(Color.Red);
for (int i = 0; i < 2 * k - 1; i += 2)
{
g.FillRectangle(brush, testChromosomesInt[centrum][i], testChromosomesInt[centrum][i + 1], 20, 20);
}
return;
}
//end of painting
public static int max(double[][] tab, int chromosomeCount)
{
double max = 0;
int k = 0;
for (int i = 0; i < chromosomeCount; i++)
{
if (max < tab[i][0])
{
max = tab[i][0];
k = i;
}
}
return k;
}
public static int[] mutation(int[] tab, int elem, int bit)
{
int mask = 1;
mask <<= bit;
tab[elem] = tab[elem] ^ mask;
return tab;
}
public static double[] crossing(double[] tab, double[] tab2, int p, int k)
{
double[] hold = new double[2 * k];
for (int i = 0; i < p; i++)
hold[i] = tab[i];
for (int i = p; i < 2 * k; i++)
hold[i] = tab2[i];
return hold;
}
//accomodation function, checks to which centre which point belongs based on distance
private static double accomodationFunction(double[][] klastry, double[][] testtab, int n, int k)
{
double Error = 0;
for (int i = 0; i < n; i++)
{
double min = 0;
int ktory = 0;
for (int j = 0; j < k; j++)
{
double dist = distance(klastry[j], testtab[i]);
if (j == 0)
{
min = dist;
}
if (min > dist)
{
min = dist;
ktory = j;
}
}
Error += min;
}
pom++;
return 1 / Error;
}
public static double distance(double[] tab, double[] tab2)
{
double dist = 0.0;
for (int i = 0; i < tab.GetLength(0); i++)
dist += Math.Pow(tab[i] - tab2[i], 2);
return dist;
}
}
The algorithm should work like so: (excuse me if not the best english)
1. Get random points (let's say 100)
2. Check into how many clusters we want to split them (the same thing I would do using k-means for example
3. Get starting population of chromosomes
4. Throu cutting on the roulette, crossing and mutation pick the best x centres, where x is the amount of clusters we want
5. Paint them.
Here are some results, and why I think it's wrong: (it's using 100 points, 5 clusters)
k-means:
lbg:
genetic(without colors now):
I hope this clarifies a bit.
I'm trying to make a program that: When given a 4 digit number (for example, 1001) it sums the digits of that number, for 1001 this is 1 + 0 + 0 + 1 = 2, than it finds all sequences of 6 numbers from 1 to 6 (including permutations, i.e. 1*1*1*1*1*2 is different than 2*1*1*1*1*1) whose product is that number.
The result should be printed on the console in the following format: each sequence of 6 numbers, with their Morse representation, separated with a single pipe: 1 is .---- , 2 is ..---: .----|.----|.----|.----|..---|, on a new row the next permutation: .----|.----|.----|..---|.----| and so on.
The problem is, my solution doesn't show the correct answers, not even the correct number of them.
Here's my code (and please, if possible, tell me where my mistake is, and not some one line hack solutions to the problem with LINQ and regex and God knows what):
string n = Console.ReadLine();
string[] digitsChar = new string[n.Length];
for (int i = 0; i < 4; i++)
{
digitsChar[i] = n[i].ToString();
}
int[] digits = new int[digitsChar.Length];
for (int i = 0; i < 4; i++)
{
digits[i] = Convert.ToInt32(digitsChar[i]);
}
int morseProduct = digits.Sum();
Console.WriteLine(morseProduct);
List<int> morseCodeNumbers = new List<int>();
for (int i = 1; i < 6; i++)
{
for (int j = 1; i < 6; i++)
{
for (int k = 1; i < 6; i++)
{
for (int l = 1; i < 6; i++)
{
for (int m = 1; i < 6; i++)
{
for (int o = 1; o < 6; o++)
{
int product = i * j * k * l * m * o;
if (product == morseProduct)
{
morseCodeNumbers.Add(i);
morseCodeNumbers.Add(j);
morseCodeNumbers.Add(k);
morseCodeNumbers.Add(l);
morseCodeNumbers.Add(m);
morseCodeNumbers.Add(o);
}
}
}
}
}
}
}
int numberOfNumbers = morseCodeNumbers.Count;
string[] morseCodes = new string[] { "-----", ".----", "..---", "...--", "....-", "....." };
for (int i = 0; i < numberOfNumbers; i++)
{
int counter = 0;
if (i % 5 == 0)
{
Console.WriteLine();
counter = 0;
}
if (counter < 5)
{
int index = morseCodeNumbers[i];
Console.Write(morseCodes[index] + "|");
counter++;
}
A lot of your for-loop conditions refer to i instead of j,k,l and m. The same for the increment part. For example:
for (int j = 1; i < 6; i++)
should be
for (int j = 1; j < 6; j++)
Furthermore if the range is from 1 to 6 you need to change < to <=, see:
for (int i = 1; i <= 6; i++)
You don't need to convert the string to a string array to get the int array of digits btw, so while this is correct:
for (int i = 0; i < 4; i++)
{
digitsChar[i] = n[i].ToString();
}
int[] digits = new int[digitsChar.Length];
for (int i = 0; i < 4; i++)
{
digits[i] = Convert.ToInt32(digitsChar[i]);
}
you could it do like that (sry for LINQ):
var digits = n.Select(c=>(int)char.GetNumericValue(c) ).ToArray();