Are there solutions for the following problem?
A user enters an X coordinate, Y coordinate, length, and (optional)
number. If a number was entered, print a straight line with the
specified length, followed by the (x,y) coordinates. If n=2, print
bisecting lines with the specified length. If n=3, print a triangle
where the lines are the specified length.
Assuming you want ASCII drawings, here's how this would work. Note that I'm just providing an outline of how this would work, since I don't want to answer the interview question for you. Also, this is not production-quality since there's no validation (or differentiation between lack of input and invalid input).
First, let's ask the user for their input. Console.ReadLine is how you do this. Since we'll be getting input four times, let's make it a method. The return type can be int since everything we're getting from the user is a number. We'll print the prompt (passed in as an argument) with Console.WriteLine and then return the result of Console.ReadLine after converting it to an int (do you need validation)? Since n is optional, maybe return something like -1 if the user doesn't enter anything.
Store the results so that we can use them later in our calculations. Use an if... else if (or switch) statement to determine if n was supplied by the user and take action accordingly. We can call different methods depending on whether we want to draw a line, two bisecting lines, or a triangle.
Is the actual drawing the problem? I'm having trouble understand exactly where you need help, and the drawing of the shapes would be more complicated. For now, though, this should get you on the right track.
Related
I am struggeling with a little homework task. The point of the task is to create a program that will work out the final averages for a given set of grades.
The format of a grade line is:
N grades1, grades2, …………., grades5
Where N is total number of students and grades is the ith score. All
scores must be between 0 and 100.
The program reads the grades from the user, calculate and display the
average.
I am at the stage of trying to logically lay it out on paper, but I am stuck.
I am not asking for an answer but just merely a point in the right direction, since I am new to c#.
riorio's answer is fine, I just want to add pointers to some relevant documentation that might be useful for you for the C#/.NET part. Feel free to keep this information hidden and use it only as a last resort, if you prefer:
The Console class for reading/displaying data from/to the user. Look at the ReadLine and WriteLine methods. (I'm assuming you are developing a console application).
The int.TryParse method for parsing/validating the input.
C#'s for and while for the data collection loop.
You might want to use a List to store the collected grades.
And finally, LINQ's Sum method might be useful for you to calculate the average.
You might need to take care with this too: Number casting and type conversions.
Maybe this can help you:
Read N from the input line. --> think how you can break the input line
Do a loop for N times.
Validate each input. --> think what validation do you need and how you can do them
Calculate the average.
Display the average.
I wanted to know how to word-wrap in C# when I came across a very good solution to my problem on word-wrapping text in a line in this URL. Unfortunately, I do not have enough reputations to ask the OP directly about one specific problem I am having(and most likely people dealing with this will be having indefinitely)
Problem Description:
I can word-wrap a string if it needs to be word-wrapped with this code:
Graphics PAddress = e.Graphics;
SizeF PAddressLength = PAddress.MeasureString("Residential Address: " + RAddressTextBox.Text, new Font(fontface, fontsize, FontStyle.Regular),700);
PAddress.DrawString("Residential Address: "+PAddressLength + RAddressTextBox.Text, new Font(fontface, fontsize, FontStyle.Regular), Brushes.Black, new RectangleF(new Point(pagemarginX, newline()),PAddressLength),StringFormat.GenericTypographic);
However, I could not find the place to receive a trigger whenever the word-length overflows from a single line.
for example:
In LINE-2 of that code, whenever the wordlength exceeds 700px, it moves to the next line. It does that by following the RectangleF to wordwrap. It is doing so automatically, which is a problem since that makes it difficult to know whether it has crossed 700px or not.This is the format in which information is displayed whenever I tried to print PAddressLength:
{Width=633.1881, Height=47.14897}
I am thinking that If I can extract the value of width from that using PAddressLength.Width ,then I can partially solve this problem. But with that, I will need to calculate if the remaining space(i.e 700px - 633.1881px ) will accommodate the next word or not(if there is one)
BREAKING DOWN THE PROBLEM:
I already know how to word-wrap when there is a string longer than what specify by using Graphics.MeasureString as given in this solution in another question.
But that^ process happens automatically, so I want to know how to detect if the word-wrap has occured(and how may lines it has wrapped with each line being 700px width maximum)
I need to know the number of lines that have been wrapped in order to know the number of times to execute newline() function that I wrote, which gives appropriate line spacing upon executing each time.
ADDITIONALLY, (bonus question; may or maynot solve) Is there some way to extract the value 633.1881 and then calculate whether the next word fits in ( 700 - 633.1881 )px space or not?
There is an overload to MeasureString that returns the number of lines used in an out parameter: https://msdn.microsoft.com/en-us/library/957webty%28v=vs.110%29.aspx
I'm not sure if SO is the proper place for asking this, if it's not, I will remove the question and try it in some other place. Said that I'm trying to do the following:
I have a List<double> and want to replace the block of values whose values are situated very close (say 0.75 in this example) to a single value, representing the mean of the replaced values.
The values that are isolated, or alone, should not be modified.
Also the replaced block can't be longer than 5.
Computing the mean value for each interval from 0, 5, 10.. would not provide the expected results.
It happened many times that LINQ power surprised me gladly and I would be happy if someone could guide me in the creation of this little method.
What I've thought is to first find the closest values for each one, calculate the distance, if the distance is less than minimum (0.75 in this example) then assign those values to the same block.
When all values are assigned to their blocks run a second loop that replaces each block (with one value, or many values) to its mean.
The problem that I have in this approach is to assign the "block": if several values are together, I need to check if the evaluating value is contained in another block, and if it so, the new value should be in that block too.
I don't know if this is the right way of doing this or I'm over complicating it.
EDIT: the expected result:
Although you see two axes only one is used, the List is 1D, I should have drawn only the X axis.
The length of the lines that are represented is irrelevant. It's just to mark on the axis where the value is situated.
It turns out that MSDN has already done this, and provided an in-depth example application with code:
Data Clustering - Detecting Abnormal Data Using k-Means Clustering
In my project i face a scenario where i have a function with numerous inputs. At a certain point i am provided with an result and i need to find one combination of inputs that generates that result.
Here is some pseudocode that illustrates the problem:
Double y = f(x_0,..., x_n)
I am provided with y and i need to find any combination that fits the input.
I tried several things on paper that could generate something, but my each parameter has a range of 6.5 x 10^9 possible values - so i would like to get an optimal execution time.
Can someone name an algorithm or a topic that will be useful for me so i can read up on how other people solved simmilar problems.
I was thinking along the lines of creating a vector from the inputs and judjing how good that vektor fits the problem. This sounds awful lot like an NN, but there is no training phase available.
Edit:
Thank you all for the feedback. The comments sum up the Problems i have and i will try something along the lines of hill climbing.
The general case for your problem might be impossible to solve, but for some cases there are numerical methods that can help you solve your problem.
For example, in 1D space, if you can find a number that is smaller then y and one that is higher then y - you can use the numerical method regula-falsi in order to numerically find the "root" (which is y in your case, by simply invoking the method onf(x) -y).
Other numerical method to find roots is newton-raphson
I admit, I am not familiar with how to apply these methods on multi dimensional space - but it could be a starter. I'd search the literature for these if I were you.
Note: using such a method almost always requires some knowledge on the function.
Another possible solution is to take g(X) = |f(X) - y)|, and use some heuristical algorithms in order to find a minimal value of g. The problem with heuristical methods is they will get you "close enough" - but seldom will get you exactly to the target (unless the function is convex)
Some optimizations algorithms are: Genethic Algorithm, Hill Climbing, Gradient Descent (where you can numerically find the gradient)
I'm a student and I got a homework i need some minor help with =)
Here is my task:
Write an application that prompts the user to enter the size of a square and display a square of asterisks with the sides equal with entered integer. Your application works for side’s size from 2 to 16. If the user enters a number less than 2 or greater then 16, your application should display a square of size 2 or 16, respectively, and an error message.
This is how far I've come:
start:
int x;
string input;
Console.Write("Enter a number between 2-16: ");
input = Console.ReadLine();
x = Int32.Parse(input);
Console.WriteLine("\n");
if (x <= 16 & x >= 2)
{
control statement
code
code
code
}
else
{
Console.WriteLine("You must enter a number between 2 and 16");
goto start;
}
I need help with...
... what control statment(if, for, while, do-while, case, boolean) to use inside the "if" control.
My ideas are like...
do I write a code that writes out the boxes for every type of number entered? That's a lot of code...
..there must be a code containing some "variable++" that could do the task for me, but then what control statement suits the task best?
But if I use a "variable++" how am I supposed to write the spaces in the output, because after all, it has to be a SQUARE?!?! =)
I'd love some suggestions on what type of statements to use, or maybe just a hint, of course not the whole solution as I am a student!
It's not the answer you're looking for, but I do have a few suggestions for clean code:
Your use of Int32.Parse is a potential exception that can crash the application. Look into Int32.TryParse (or just int.TryParse, which I personally think looks cleaner) instead. You'll pass it what it's parsing and an "out" parameter of the variable into which the value should be placed (in this case, x).
Try not to declare your variables until you actually use them. Getting into the habit of declaring them all up front (especially without instantiated values) can later lead to difficult to follow code. For my first suggestions, x will need to be declared ahead of time (look into default in C# for default instantiation... it's, well, by default, but it's good information to understand), but the string doesn't need to be.
Try to avoid using goto when programming :) For this code, it would be better to break out the code which handles the value and returns what needs to be drawn into a separate method and have the main method just sit around and wait for input. Watch for hard infinite loops, though.
It's never too early to write clean and maintainable code, even if it's just for a homework assignment that will never need to be maintained :)
You do not have to write code for every type of number entered. Instead, you have to use loops (for keyword).
Probably I must stop here and let you do the work, but I would just give a hint: you may want to do it with two loops, one embedded in another.
I have also noted some things I want to comment in your code:
Int32.Parse: do not use Int32, but int. It will not change the meaning of your code. I will not explain why you must use int instead: it is quite difficult to explain, and you would understand it later for sure.
Avoid using goto statement, except if you were told to use it in the current case by your teacher.
Console.WriteLine("\n");: avoid "\n". It is platform dependent (here, Linux/Unix; on Windows it's "\r\n", and on MacOS - "\n\r"). Use Environment.NewLine instead.
x <= 16 & x >= 2: why & and not ||?
You can write string input = Console.ReadLine(); instead of string input; followed by input = Console.ReadLine();.
Since it's homework, we can't give you the answer. But here are some hints (assuming solid *'s, not white space in-between):
You're going to want to iterate from 1 to N. See for (int...
There's a String constructor that will allow you to avoid the second loop. Look at all of the various constructors.
Your current error checking does not meet the specifications. Read the spec again.
You're going to throw an exception if somebody enters a non-parsable integer.
goto's went out of style before bell-bottoms. You actually don't need any outer control for the spec you were given, because it's "one shot and go". Normally, you would write a simple console app like this to look for a special value (e.g., -1) and exit when you see that value. In that case you would use while (!<end of input>) as the outer control flow.
If x is greater or equal to 16, why not assign 16 to it (since you'll eventually need to draw a square with a side of length 16) (and add an appropriate message)?
the control statement is:
for (int i = 0; i < x; i++)
{
for ( int j = 0; j < x; j++ )
{
Console.Write("*");
}
Console.WriteLine();
}
This should print a X by X square of asterisks!
I'ma teacher and I left the same task to my students a while ago, I hope you're not one of them! :)