Display every single combination of lower case letters - c#

I am trying to figure out how to print every single combination of lower case letters starting at A, B, C , .. , Z AA, AB , .., ZZ ... AAA, AAB, AAC ... HWESA, HWESB, HWESC ... etc and I want the program to keep printing these endlessly, growing in length by 1 each time Z is found as the last letter.
Code that is have seen online is like this
for(int a = 0; a < alphabet.length; a++)
{
Console.WriteLine(alphabet[a]);
for(int b = 0; b < alphabet.length; b++)
{
Console.WriteLine(alphabet[a]+alphabet[b]);
//With however many for loops you want which correspond to string length
}
}
However, this doesn't work for me because I want the length to go till infinite (or in my program to stop when it matches a hard-coded string).

I have tried the same in java with recursive method , hope you understand the logic and write down in C#.You can check the whole program in the below shared link.
size - if 1 means a,b,c...z
if 2 means aa,ab...zz
public static void recursion(long size,String prefix)//Recursive method
{
// Base case: size is 0, print prefix
if(size==0)
{ System.out.println(prefix);
return;
}
// One by one add all characters from set and recursively
// call for size equals to size-1
for(int i=0;i<26;i++)
{
// Next character of input added
String newPrefix = prefix + s[i];
// Size is decreased, because we have added a new character
recursion(size-1,newPrefix);
}
}
Click Here to View Full Code

Related

I'm calculating the sum of numbers in a series but I only want the console to output the final sum but I don't know how

int a=Convert.ToInt32(Console.ReadLine());
int b=Convert.ToInt32(Console.ReadLine());
int c = a / b;
int b2 = b;
for(int i=0; i<=c; i++)
{
b += (b2 * i);
Console.WriteLine(b-b2);
}
this is basic code that asks for a base number, and a secondary number. only numbers divisible by the second number are added together. I only want to output the final number, but right now it outputs every step it takes and I'm to noob to know an easy solution.
Write the console.WriteLine() Outside the for loop to avoid printing it in every step.

Start array search on the END of the (2D) array

I'd like to start the search of an int in my array on the end of the array, not at the beginning. How do I do this?
Please keep in mind that it's a 2D array.
edit someone asked how I search from the start:
In my code file I'm printing a matrix from 8x8 displaying random numbers (1 - 10). The user gives a number to search in the matrix, and the code gives back the position in which the number is FIRST found:
Position position = new Position();
Position LookForNumber(int[,] matrix, int findNumber)
{
for (int r = 0; r < matrix.GetLength(0); r++)
{
for (int c = 0; c < matrix.GetLength(1); c++)
{
if (matrix[r, c] == findNumber)
{
Console.WriteLine("Your number {0} first appears on position {1},{2}", findNumber, r, c);
position.row = r;
position.column = c;
return position;
}
}
}
return position;
}
Now I'd like to find the last position of the number that the user gave up.
To Search a 2D array you would need 2 loops, however you may do the loops in revearse order:
Position LookForNumber(int[,] matrix, int findNumber)
{
Position position = new Position();
for (int r = matrix.GetLength(0) - 1; r >= 0 ; r--)
{
for (int c = matrix.GetLength(1) - 1; c >= 0 ; c--)
{
if (matrix[r, c] == findNumber)
{
Console.WriteLine("Your number {0} first appears on position
{1},{2}", findNumber, r, c);
position.row = r;
position.column = c;
return position;
}
}
}
return null;
}
The fact the array is 2D is irrelevant to your issue.
See how the most regular basic loops works?
for (int i = 0; i < array.length ; i++)
{
...
}
You're essentially doing this, if you had to translate code to english
For all elements, starting with 0 that we're assigning to i, stopping before we reach array.length, and adding 1 to i between each iteration, do the following (...)
So all you have to do really, is change the parameters of the loop.
For example, you could say your starting point (which is i), could be something other than 0. What would you use instead of zero if you want to start at the end of your array?
Then, if you're starting at the end, can you really ADD values to i between each iterations ? Not really, you'd go out of bounds, so what should you do instead of i++ ?
At that point, you need a stopping point if you're iterating from end to start. And the answer lies in the question : my stopping point is the start of the array. So the middle parameter of your loop (which is the stopping point) should be something that represents the start of your array. How would you write that down?
Note that you could also iterate every second element now that you understand the logic, for example.
And the fact you're in a 2D loop just means you need one inner loop inside your main loop, which will work the same way as the outer loop. Just imagine the indexes as a canvas with coordinates, instead of just a line with points.
If you don't understand all I meant I'll just write down the answer, but I think the explanation is clear enough that you will understand :)

How to write in multiple positions in a console application at the same time? C#

I want lines as many as the width of the console to simultaneously write downwards one char to the height of the console. I've done most of it, but it goes from top to bottom to right etc...
If you need help picturing what I mean, think of the matrix code rain.
int w = Console.WindowWidth;
int h = Console.WindowHeight;
int i = 0;
while (i < w)
{
int j = 0;
while (j < h)
{
Thread.Sleep(1);
Console.SetCursorPosition(i, j);
Console.Write(".");
j++;
}
i++;
}
What I would do is construct a List<string> lines; that would contain the lines you want to write to the console window, where each line is as wide as the console width. Then just print the list out to the console window in reverse order, so the first line (at lines[0]) will always be the last one printed, and will always be at the bottom of the console window.
Sample Implementation -- someone mentioned this might be homework. I did not think so, but if it is, then please try your own implementation of the above idea first.
We can add new items to the list in the same loop that we use to print out its items. Before we add a line, however, we first check to see if there are already as many lines in the list as there are in the console window (Console.WindowHeight). If there are, then we just remove the line at lines[0] before we add a new one. In this way, the List<string> lines is "scrolling" along with the console window.
The scrolling speed is controlled by a Thread.Sleep, but this code could easily be added to a Timer instead, so that other work could happen in the background (like if this was intended to be a "screensaver", and you wanted to wait for user input to "wake up"). But no matter how we decide to implement the speed, I decided to create an enum with values that represent the number of milliseconds a Thread.Sleep implementation would use:
class Program
{
enum MatrixCodeSpeed
{
Fastest = 0,
Faster = 33,
Fast = 67,
Normal = 100,
Slow = 333,
Slower = 667,
Slowest = 1000
}
I would also create a helper method that creates a "random" line for you. It could take in an integer that specifies the "density", which means how many characters you'd want in the line. density represents a percentage, so if 10 is specified, then we pick a random number between 0 and 99, and if it's less than 10 then we add a random matrix character to the string (otherwise we add a space character).
Also, in order to replicate the matrix a little closer, I've also chosen 4 different characters to print, each one slightly darker than the previous. This adds to the three dimensional effect, where the faded blocks look further away than the solid ones:
private static Random rnd = new Random();
// Add whatever 'matrix' characters you want to this array. If you prefer to have one
// character chosen more often than the others, you can write code to favor a specific
// index, or just add more instances of that character to the array below:
private static char[] matrixChars = new[] { '░', '▒', '▓', '█' };
static string GetMatrixLine(int density)
{
var line = new StringBuilder();
for (int i = 0; i < Console.WindowWidth; i++)
{
// Choose a random number from 0-99 and see if it's greater than density
line.Append(rnd.Next(100) > density
? ' ' // If it is, add a space to reduce line density
: matrixChars[rnd.Next(matrixChars.Length)]); // Pick a random character
}
return line.ToString();
}
Next, we have the main method, which populates a list with random lines (using a density of 10%), then prints them out one at a time, in reverse order, in an endless loop (removing the first line if we need to):
static void Main()
{
var lines = new List<string>();
var density = 10; // (10% of each line will be a matrix character)
var speed = MatrixCodeSpeed.Normal;
// Hide the cursor - set this to 'true' again before accepting user input
Console.CursorVisible = false;
Console.ForegroundColor = ConsoleColor.DarkGreen;
while (true)
{
// Once the lines count is greater than the window height,
// remove the first item, so that the list "scrolls" also
if (lines.Count >= Console.WindowHeight)
{
lines.Remove(lines[0]);
}
// Add a new random line to the list, which will be the new topmost line.
lines.Add(GetMatrixLine(density));
Console.SetCursorPosition(0, 0);
// Print the lines out to the console in reverse order so the
// first line is always last, or on the bottom of the window
for (int i = lines.Count - 1; i >= 0; i--)
{
Console.Write(lines[i]);
}
Thread.Sleep(TimeSpan.FromMilliseconds((int)speed));
}
}
}
Here's a gif of it in action, up to the point where the screen is full (then the gif repeats, but the code version continues to scroll normally):
The task smells like an assignment, so I'm guiding you instead feeding the implementation. It is not ethical to feed you with an answer if it is a homework.
You are looking for a better fit of algorithm. The stated algorithm fill the console from top to bottom, as it iterate to fill through the Y-axis first (the nested loop) and followed by the X-axis (the outer loop).
What is needed is to iterate x-axis and y-axis alternatively so that it looks like it fills from the top left corner to the bottom right corner.
// 1 step to (0,0)
*
// 3 steps to (1,1)
**
**
// 5 steps for reaching (2,2)
***
***
***
// 7 steps for reaching (3,3)
****
****
****
// 9 steps for reaching (4,4) and 11 steps for (5,5)...
// I do think everyone could get this pattern
This draft would also be the final outcome of what it looks like.
Instead of filling them all at the same time, what you need is actually get the thread sleep after it reach the next square point.
(Computers are so fast that it probably do all its work to feed your screen within a second and the black console window is gone without any notice.)
At the time you posted the question, I'm also solving it from the very beginning. I thought of filling X and Y axis alternatively is the solution, but stopping at each time that the square expands is far more important to get the effect.
It is not a threading problem tag either at my point of view.
Let's sum up the above pattern:
Assume i and j are x and y coordinates respectively.
Each iteration takes you from (i, j) and n*2+1 steps to reach
(i+1,j+1)
Note that we are zero-based in this example.
We are about to construct the loop:
The n*2+1 step number is useful. It means you need to fill x-axis for
n times and y-axis for n times, and finally get the diagonal grid
(n+1,n+1) done.
In each inner loop, we first render the X frontier along y-axis and
then render the Y frontier along x-axis.
Let say the cycle start with the checkpoint (n,n), where n=3, and we
slept for a while, so we are in n=4 now.
To achieve this, we'd better first navigate to (n+1,0) then fill up
to (n+1,n)
Afterwards we navigate to (0,n+1) and fill to (n+1,n+1)
Then we are in m=n+1 now (sounds like a mathematical proving :(
The loop would be
//calculate how many checkpoints (n)
int checkpoints = 1080;
//n should indicate the actual turn we are instead of naming the total turns like sucks
//The main, the outermost For-loop
for (int n=0;n<checkpoints;n++)
{
// The nested step
for (int y=0;y<n;y++)
{
// Just fill in (n+1, y) grid
Console.SetCursorPosition(n+1, y);
Console.Write(".");
}
for (int x=0;x<n+1;x++)
{
// Just fill in (x, n+1) grid
Console.SetCursorPosition(x, n+1);
Console.Write(".");
}
// Upon completion of each main cycle we have a sleep, yah
Thread.Sleep(100);
}
Well, I expect the program to crash when the console size is smaller than 1080x1080.
This algorithm could only get you a square to fill, and a typical monitor with resolution 1920x1080 just fails as it is 16:9. This is intentional, if you're doing homework you need to configure it before shipping it to your teacher. (I've got no chance to do an assignment as I self learned programming :(
(The site continuously urging me to format my code, this has been half an hour and I just didn't do things wrong. So I decided to post it bit by bit to debug that. Finally I've got the job done...)
If you just want to write one line at a time you can use this:
int w = Console.WindowWidth;
int h = Console.WindowHeight;
int i = 0;
while (i < h)
{
Console.WriteLine(new string('.', w-1));
Thread.Sleep(20);
i++;
}
Just a bit of modification allow the code to simulate the matrix code rain.
int w = Console.WindowWidth;
int h = Console.WindowHeight;
int i = 0;
while (i < h)
{
int j = 0;
string s = "";
Thread.Sleep(10);
while (j < w)
{
Console.SetCursorPosition(j, i);
s += ".";
j++;
}
Console.Write(s);
i++;
}
basically what i did here is just some restructuring of the logic and putting in the proper delays at the right position. Hope it helps.

Print ASCII of a triangle shape with variable input

Struggling with the print. I know it should be two for loops to print out the repeated letters, however, having problems to indent the lines. it should be a simple console C# program to print out the shape like below with a input 3.
XXXXX
XXX
X
With input 4 it should be like
XXXXXXX
XXXXX
XXX
X
Here is my code. Two for loops get the letters correctly but the lines all lined up at the left, not center.
static void Main(string[] args)
{
string num = Console.ReadLine().Trim();
int n = Convert.ToInt32(num);
int k=1;
for(int i = n; i>=1; i--)
{
Console.WriteLine("\n");
Console.WriteLine("".PadLeft(n));
for (int j = (2*i-1); j>=1;j--)
{
Console.Write("0");
}
}
Console.Read();
}
The statement:
Console.WriteLine("".PadLeft(n));
is the right idea but it's not quite there.
In your case, n is the number of lines you wish to print and is invariant. The number of spaces you need at the start of each line should begin at zero and increase by one for each line.
In any case, printing any number of spaces followed by newline (because it's WriteLine) is not what you want, you should be using Write instead.
So the code between int n = Convert.ToInt32(num); and Console.Read(); would be better off as something like:
for (int lineNum = 0; lineNum < n; lineNum++) {
int spaceCount = lineNum;
int xCount = (n - lineNum) * 2 - 1;
Console.Write("".PadLeft(spaceCount));
Console.WriteLine("".PadLeft(xCount, 'X'));
}
You'll notice some other changes there. First, I've used more meaningful variable names, something I'm a bit of a stickler for - using i is okay in certain circumstances but I often find it's more readable to use descriptive names.
I've also used PadLeft to do the X string as well, so as to remove the need for an inner loop.

whats wrong in this logic of finding longest common child of string

i came up with this logic to find longest common child of two strings of equal length but it runs successfuly only on simple outputs and fails others,pls guide me what i am doing wrong here.
String a, b;
int sum = 0;
int[] ar,br;
ar = new int[26];
br = new int[26];
a = Console.ReadLine();
b = Console.ReadLine();
for (int i = 0; i < a.Length; i++)
{
ar[(a[i] - 65)]++;
br[(b[i] - 65)]++;
}
for(int i =0;i<ar.Length;i++)
{
if (ar[i] <= br[i]) { sum += ar[i]; }
else sum += br[i];
}
Console.Write(sum);
Console.ReadLine();
output:
AA
BB
0 correct.
HARRRY
SALLY
2 correct
for both above input it runs but when i submit for evaluation it fails on their test cases.i cant access their testacase on which my logic fails.i wanna know where does my logic fails.
Your second loop is all wrong. It is simply finding the count of characters that occur in both the array and the count is only updated with the the no. of the common characters contained in the string containing the least no. of these common characters.
refer this link for the correct implementation.
http://en.wikibooks.org/wiki/Algorithm_Implementation/Strings/Longest_common_substring#Retrieve_the_Longest_Substring
Also convert your input to uppercase characters using String.ToUpper before you use the input string.

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