for school practice I have to make a windows application in C# that takes a input number and draws a square of X's with side N. I have to do it with a loops and i can't use any preset commands. (For example math.pow i cannot use) (I've included a picture of the assignment.) I've already mode this program in a console application and there it worked fine.
I think that i'm very close of solving it but can't figure out what the last step is. I would love to know what i'm missing and how i should solve this.
See the assignment
This is my code now:
int n;
n = int.Parse(txt_input.Text);
//upper part
for (int i = 0; i < n; i++)
{
lbl_output.Text = "X";
lbl_output.Text = "\n";
}
//middel part
for (int i = 0; i < n - 2; i++)
{
lbl_output.Text = "X";
for (int j = 0; j < n - 2; j++) lbl_output.Text = " ";
lbl_output.Text = "X";
lbl_output.Text = "\n";
}
//upper part
for (int i = 0; i < n; i++)
{
lbl_output.Text = "X";
lbl_output.Text = "\n";
}
Try this:
int n = int.Parse(txt_input.Text);
var sb = new StringBuilder();
for (int j = 0; j < n; j++)
{
sb.Append('X');
}
sb.AppendLine();
for (int i = 0; i < n - 2; i++)
{
sb.Append('X');
for (int j = 0; j < n - 2; j++)
{
sb.Append(' ');
}
sb.Append('X');
sb.AppendLine();
}
for (int j = 0; j < n; j++)
{
sb.Append('X');
}
lbl_output.Text = sb.ToString();
Try this;
int n = int.Parse(txt_input.Text);
//upper part
for (int i = 0; i < n; i++)
{
lbl_output.Text += "X";
}
lbl_output.Text += "\n";
//middel part
for (int i = 0; i < n - 2; i++)
{
lbl_output.Text += "X";
for (int j = 0; j < n - 2; j++)
lbl_output.Text += " ";
lbl_output.Text += "X";
lbl_output.Text += "\n";
}
//upper part
for (int i = 0; i < n; i++)
{
lbl_output.Text += "X";
}
You forget to use += which will append the text with the previous assigned text. Also you had some unnecessary new lines in your code.
Need to append to the string. There's a couple ways of doing this. Tho '+=' should work fine. += is short for variable = variable + newValue
int n = int.Parse(txt_input.Text);
string output = "";
for(int x = 0; x < n; x++) //rows
{
if (x == 0 || x == n-1) //first / last row all x
for(int y = 0; y < n; y++)
{
output += "x";
}
else //other rows
for(int y = 0; y < n; y++)
{
output += (y == 0 || y == n - 1) ? "x" : " "; //if first or last column "X" else " "
}
output += "\n"; //at the end of each row a return
}
lbl_output.Text = output;
You can see it run in the browser here: https://dotnetfiddle.net/wiYfjX
Use two loops. One for the width of the square and one for the height of the square.
Give this a try and replace the parameter from what is in the txt_input control. (Just place the function whereever you want in your code (button_click for example) instead of the form load.
private void Form1_Load(object sender, EventArgs e)
{
lblOutput.Text = GenerateSquare(5);
}
private string GenerateSquare(int n)
{
string square = "";
for (int w = 0; w < n; w++)
{
for (int h = 0; h < n; h++)
{
// top or bottom line
if (w == 0 || w == n - 1)
{
square += "x";
}
else // sides
{
if (h == 0 || h == n - 1)
{
square += "x";
}
else square += " ";
}
// change line
if (h == n - 1)
square += "\n";
}
}
return square;
}
Related
I am working on an A* Pathfinding method that uses a custom class instead of nodes, but am having issues with my loops. The first for loop using int i is able to go up to 3 (Player1.instance.movement = 3), but I need to use an if statement inside of that loop to check if the target position has already been found. I am wondering if it is possible to break my for loop when my If statement is false.
public void GetNeighbors(Tile originTile)
{
Tile originalTile = originTile;
nextTile.Clear();
int minX = 0;
int minY = 0;
var originCostFunc = Mathf.Infinity;
for (int i = 0; i < Player1.instance.movement; i++)
{
for (int x = -1; x <= 1; x++)
{
for (int y = -1; y <= 1; y++)
{
if (x != y && y != x)
{
var costX = Mathf.Abs((originTile.transform.position.x + x) - originalTile.transform.position.x);
var costY = Mathf.Abs((originTile.transform.position.y + y) - originalTile.transform.position.y);
var distanceX = Mathf.Abs(targetPos.transform.position.x - (originTile.transform.position.x + x));
var distanceY = Mathf.Abs(targetPos.transform.position.y - (originTile.transform.position.y + y));
var costFunc = costX + costY + distanceX + distanceY;
if (costFunc <= originCostFunc)
{
originCostFunc = costFunc;
minX = x;
minY = y;
Debug.Log($"x: {x}, y: {y}");
}
}
}
}
nextTile.Add(GridManagerHandPlaced.instance.GetTileAtPosition(new Vector2(originTile.transform.position.x + minX, originTile.transform.position.y + minY)));
if (nextTile[i] != targetPos)
{
originTile = nextTile[i];
}
else
{
break;
}
}
DisplayPath();
}
You can break loop several times by condition.
bool breakLoop = false;
for (int i = 0; i < length; i++)
{
for (int j = 0; j < length; j++)
{
for (int k = 0; k < length; k++)
{
breakLoop = nextTile == target;
if (breakLoop)
break;
}
if (breakLoop)
break;
}
if (breakLoop)
break;
}
Or move search logic to separated method and return a value from any number of nested loops
string path = FindPath();
Display(path);
string FindPath()
{
for (int i = 0; i < length; i++)
{
for (int j = 0; j < length; j++)
{
for (int k = 0; k < length; k++)
{
if (nextTile == target)
return nextTile;
}
}
}
return null;
}
Never use goto operator.
This is one of the few valid cases where I'd use goto. In-fact, this is the example given in the docs for when it should be used.
void CheckMatrices(Dictionary<string, int[][]> matrixLookup, int target)
{
foreach (var (key, matrix) in matrixLookup)
{
for (int row = 0; row < matrix.Length; row++)
{
for (int col = 0; col < matrix[row].Length; col++)
{
if (matrix[row][col] == target)
{
goto Found;
}
}
}
Console.WriteLine($"Not found {target} in matrix {key}.");
continue;
Found:
Console.WriteLine($"Found {target} in matrix {key}.");
}
}
Note the syntax for the label is simply myLabel: and you can place it anywhere in procedurally executable code.
For sake of covering other ways of handling this situation, here is the boolean solution.
bool breakLoops = false;
for (int i = 0; i < length1; i++)
{
for (int ii = 0; ii < length2; ii++)
{
for (int iii = 0; iii < length3; iii++)
{
if (breakingCondition)
{
breakLoops = true;
break;
}
}
if (breakLoops) break;
}
if (breakLoops) break;
}
Simple and straightforward, but requires a break condition check at the end of each loop that you want to break out of.
I need make symmetric letter “W” in string Array
get_w() Is method that should return string array that contains letter "W"
get_w(5) # should return:
public string[] GetW(int h)
{
if (h < 2) return new string[h];
int row = 0;
int stars_number = h * 4 - 3;
int times = 0;
StringBuilder[] c = new StringBuilder[h];
for(int a = 0; a < h; a++)
{
c[a] = new StringBuilder();
c[a].Length = stars_number;
}
for (int i = 0; i < stars_number; i++)
{
if (i == h - 1) times = 1;
if (i == stars_number-2 * h + 1) times = 2;
if (i == stars_number - h) times = 3;
c[row][i] = '*';
if (row < h - 1 && (times == 0 || times == 2))
{
row += 1;
}
else
{
row -= 1;
}
}
string []str = new string[h];
for(int i = 0; i < h; i ++)
{
str[i] = c[i].ToString();
}
return str;
}
if I compile it in a VS i get no errors.Here is an example of the result
This task is taken from the Codewars
but if I try to test on Codewars with the code I described above, I get this error
Edited:I changed returning array with "h" length to empty array and had got this
i found the task solution by replacing charters that equal '\0' with character ' '
here is working code
public string[] GetW(int h)
{
if (h < 2) return new string[]{};
int row = 0;
int stars_number = h * 4 - 3;
int times = 0;
StringBuilder[] c = new StringBuilder[h];
for(int a = 0; a < h; a++)
{
c[a] = new StringBuilder();
c[a].Length = stars_number;
}
for (int i = 0; i < stars_number; i++)
{
if (i == h - 1) times = 1;
if (i == stars_number-2 * h + 1) times = 2;
if (i == stars_number - h) times = 3;
c[row][i] = '*';
if (row < h - 1 && (times == 0 || times == 2))
{
row += 1;
}
else
{
row -= 1;
}
}
string []str = new string[h];
for(int i = 0; i < h; i ++)
{
c[i].Replace('\0', ' ');
str[i] = c[i].ToString();
}
return str;
}
And here is result of test
I have a neural network in visual studio. for the loss function I am using a basic cost function (pred-target)**2 and after I finish an epoch I optimize the parameter functions afterwards, but the algorithm doesn't work.
No matter what is my network configuration, the predictions are not write (it is the same output for all the inputs) and the loss function is not optimized. It stays the same through all the epochs.
void calc_lyr(int x, int y, int idx, float target) // thus function calculates the neuron value based on the previous layer
{
if (x == -1 || y == 0) // if its the first layer, get the data from input nodes
{
for (int i = 0; i < neurons[y]; i++)
{
float sum = 0;
for (int j = 0; j < inputTypes.Count; j++)
{
sum += weights[x+1][j][i] * training_test[idx][j];
}
sum = relu(sum);
vals[y+1][i] = sum;
}
}
else
{
for(int i = 0; i < neurons[y]; i++)
{
float sum = 0;
for(int j = 0; j < neurons[x]; j++)
{
sum += weights[x+1][j][i] * vals[x+1][j] + biases[y][i];
}
sum = relu(sum);
vals[y+1][i] = sum;
}
}
}
void train()
{
log("Proces de antrenare inceput ----------------- " + DateTime.Now.ToString());
vals = new List<List<float>>();
weights = new List<List<List<float>>>();
biases = new List<List<float>>();
Random randB = new Random(DateTime.Now.Millisecond);
Random randW = new Random(DateTime.Now.Millisecond);
for (int i = 0; i <= nrLayers; i++)
{
progressEpochs.Value =(int)(((float)i * (float)nrLayers) / 100.0f);
vals.Add(new List<float>());
weights.Add(new List<List<float>>());
if (i == 0)
{
for (int j = 0; j < inputTypes.Count; j++)
{
vals[i].Add(0);
}
}
else
{
biases.Add(new List<float>());
for (int j = 0; j < neurons[i-1]; j++)
{
vals[i].Add(0);
float valB = (float)randB.NextDouble();
biases[i-1].Add(valB - ((int)valB));
}
}
}
float valLB = (float)randB.NextDouble();
biases.Add(new List<float>());
biases[nrLayers].Add(valLB - ((int)valLB));
for (int i = 0; i <= nrLayers; i++)
{
if (i == 0)
{
for (int j = 0; j < inputTypes.Count; j++)
{
weights[i].Add(new List<float>());
for (int x = 0; x < neurons[i]; x++)
{
float valW = (float)randW.NextDouble();
weights[i][j].Add(valW);
}
}
}
else if (i == nrLayers)
{
for (int j = 0; j < neurons[i-1]; j++) {
weights[i].Add(new List<float>());
weights[i][j].Add(0);
}
}
else
{
for (int j = 0; j < neurons[i - 1]; j++)
{
weights[i].Add(new List<float>());
for (int x = 0; x < neurons[i]; x++)
{
float valW = (float)randW.NextDouble();
weights[i][j].Add(valW);
}
}
}
}
Random rand = new Random(DateTime.Now.Millisecond);
log("\n\n");
for (int i = 0; i < epochs; i++)
{
log("Epoch " + (i + 1).ToString() + " inceput ---> " + DateTime.Now.ToString());
int idx = rand.Next() % training_test.Count;
float target = outputsPossible.IndexOf(training_labels[idx]);
for (int j = 0; j < nrLayers; j++)
{
calc_lyr(j - 1, j, idx, target);
}
float total_val = 0;
for(int x = 0; x < neurons[nrLayers - 1]; x++)
{
float val = relu(weights[nrLayers][x][0] * vals[nrLayers][x] + biases[nrLayers][0]);
total_val += val;
}
total_val = sigmoid(total_val);
float cost_res = cost(total_val, target);
log("Epoch " + (i+1).ToString() + " terminat ----- " + DateTime.Now.ToString() + "\n");
log("Eroare epoch ---> " + (cost_res<1?"0":"") + cost_res.ToString("##.##") + "\n\n\n");
float cost_der = cost_d(total_val, target);
for (int a = 0; a < weights.Count; a++)
{
for (int b = 0; b < weights[a].Count; b++)
{
for (int c = 0; c < weights[a][b].Count; c++)
{
weights[a][b][c]-=cost_der*learning_rate * sigmoid_d(weights[a][b][c]);
}
}
}
for (int a = 0; a < nrLayers; a++)
{
for (int b = 0; b < neurons[a]; b++)
{
biases[a][b] -= cost_der * learning_rate;
}
}
}
hasTrained = true;
testBut.Enabled = hasTrained;
MessageBox.Show("Antrenament complet!");
SavePrompt sp = new SavePrompt();
sp.Show();
}
How can it be changed to optimize the weights, biases and loss function? For now, when I try to debug, the weights are changing, but it is the same value for the loss function.
I solved it by using AForge.NET: link
I am trying to solve Gaussian elimination in c# using parallel-processing (in this case Parallel.For). My code is sometimes running fine and sometimes not.
I used as a starting point the code shown on the link: http://www.codeproject.com/Tips/388179/Linear-Equation-Solver-Gaussian-Elimination-Csharp .
I didn't use Parallel.For for back insertion just yet because there is problem with elimination.
Elimination Class:
public static bool Gauss(double[][] M)
{
int rowCount = (M.GetLength(0));
int temp = rowCount - 1;
//elimination
Parallel.For(0, temp, sourceRow =>
//for (int sourceRow = 0; sourceRow + 1 < rowCount; sourceRow++)//diagonal
{
for (int destRow = sourceRow + 1; destRow < rowCount; destRow++)//destination row
{
double df = M[sourceRow][sourceRow];
double sf = M[destRow][sourceRow];
for (int j = 0; j < rowCount + 1; j++) // line
{
M[destRow][j] = (M[destRow][j] * df - M[sourceRow][j] * sf) / df;
}
}
});
//back-insertion
for (int row = rowCount - 1; row >= 0; row--)
{
double f = M[row][row];
if (f == 0) return false;
for (int i = 0; i < rowCount + 1; i++) M[row][i] /= f;
for (int destRow = 0; destRow < row; destRow++)
{
M[destRow][rowCount] -= M[destRow][row] * M[row][rowCount];
M[destRow][row] = 0;
}
}
return true;
}
Generate Array:
public static double[][] GenerateArray2(int n)
{
Random rnd = new Random();
double[][] M = new double[n][];
for (int i = 0; i < n; i++)
{
M[i] = new double[n + 1]; // Create inner array
for (int j = 0; j < n + 1; j++)
M[i][j] = rnd.Next(-20, 20);
}
return M;
}
Print Array
public static string Print2(double[][] M)
{
string str = "";
int rowCount = M.GetUpperBound(0) + 1;
for (int row = 0; row < rowCount; row++)
{
for (int i = 0; i <= rowCount; i++)
{
str += M[row][i];
str += "\t";
}
str += Environment.NewLine;
}
return str;
}
Results are wrong in matrix 16x17 and up. At this point I don't know how to continue, I tried to lock M in elimination, didn't help.
Thanks for any help.
/html/body/table/tr[1]/td[2]
/html/body/table/tr[1]/td[4]
/html/body/table/tr[3]/td[2]
/html/body/table/tr[3]/td[4]
/html/body/table/tr[5]/td[2]
/html/body/table/tr[5]/td[4]
So, the index of tr[ ] would be odd numbers, and td[ ] would always be either 2 or 4.
for(int i = 1; i < bound; i += 2) {
for(int j = 2; j <= 4; j += 2) {
Console.WriteLine(
String.Format("/html/body/table/tr[{0}]/td[{1}]", i, j)
);
}
Console.WriteLine();
}
You could do something as simple as
for(tr = 1; tr < maxodd+1; tr += 2;)
{
//pseudoimplementation
/html/bod/table/tr[tr]/td[2]
/html/bod/table/tr[tr]/td[4]
}
The most naive case:
for(int i = 1; i < 6; i += 2) {
Console.WriteLine("html/body/table/tr[" + i + "]/td[2]");
Console.WriteLine("html/body/table/tr[" + i + "]/td[4]");
}