So I'm developing a minesweeper game and im assigning the mines, but I've got to check where are the mines now, in order to generate the numbers. The problem is that when I'm verifying the columns and lines I need the program not to get out of the game field.
Here's how my code looks like now:
Public Sub avisinhos(ByVal line, ByVal column)
If mat(line, column) = 0 Then
mat(line, column) = -1
numbandeiras = numbandeiras + 1
End If
For auxlinha = -1 To 1
For auxcolumn = -1 To 1
Next
Next
End Sub
How do I create a IF function to verify that I don't get out of the game field?
Best regards, joao.
pseudo code
int linestart = -1;
int lineend = 1;
int colstart = -1;
int colend = 1;
Assuming a 10 x 10 grid (zero based)
if line < 2 linestart = 0
if line > 8 lineend = 0
if column < 2 colstart = 0
if column > 8 colend = 0
For auxlinha = linestart To lineend
For auxcolumn = colstart To colend
// check
Next
Next
Personally though I wouldn't bother with the loops, they add very little to nothing
HasMineAbove = (line > 1) and (gamefield[line -1,column] = MinePresentValue
would be my approach, do it all in one.
Not to mention the huge potential confusion when auxlinha and auxcolumn are both zero...
I'm not sure exactly what your code is saying. It's a bit cryptic since you're using abbreviations and all lowercase names. You might want to try camelCasing and spelling out the words more completely, intellisense is your friend. =)
But coding style aside, if you are trying to loop through a limited range of values, you can keep your values bounded by using the modulus operator (%). For example, if you need to keep you values between 0-7 and you end up with a value of 12, just take the modulus of 8 to loop back to within range with a value of 4:
12 % 8 = 4
9 % 8 = 1
15 % 8 = 7
24 % 8 = 0
I realize this doesn't answer your specific question, but it's a handy technique might find useful.
Related
Given that val is some random integer,
and number the possible outcome:
if the value is less then &H100 ; the number is 0
if the value is less then &H10000 ; the number is 1
if the value is less then &H1000000 ; the number is 2
else ; the number is 3
I've got this:
If (val And &HFFFF0000) = 0 Then
If (val And &HFF00) = 0 Then
num = 0
Else
numb = 1
End If
ElseIf (**val** And &HFF000000) = 0 Then
numb = 2
Else
numb = 3
End If
I believe to remember that I could achieve this with a simple calculation, but I can not
wrap my head around it...
cheers..
Jhonny
edit:--- after reaction of video.baba ---
Here is half a solution:
The result is a number from 0 to 7, of witch the bits represent a non-zero byte.
A lookuptable could be used to translate it to a 2-bit value.
val >>= 8 ' move to the right, so the first byte can hold identification-bits
val += &H3FF0000 'set a bit in the first byte, if the second one is not zero
val = val And &H400FFFF
val += &H1FFFF00 'set a bit in the first byte, if the third one is not zero
val = val And &H60000FF
val += &HFFFFFF'set a bit in the first byte, if the fourth one is not zero
val >>= 24 'put the result in the last byte
number=lookuptable(val)
have not tested it for speed yet, but it feels over-complicated?
Do you mean something like:
Select Case Value
Case < &H100
Number = 0
Case < &H10000
Number = 1
Case < &H1000000
Number = 2
Case Else
Number = 3
End Select
This code is supposed to take a number and find it's prime factors.
Why does this code work with numbers like 2345 (which returns 5, 7, 67 like its supposed to) but it doesn't work with numbers like 500 and 800?
EDIT: when I say it doesn't work, the program simply does nothing and/or freezes on button click. I then have to stop the program in vb.
Dim number As Double = txtNum.Text
Dim var As Double = 2
Dim result As Double
If number > 1 Then
lst1.Items.Clear()
lst1.Items.Add("The prime factors of " & number & ":")
Do While number > 1
result = number / var
If result = Int(result) Then
lst1.Items.Add(var)
number = result
End If
var = var + 1
Loop
Else
lst1.Items.Clear()
lst1.Items.Add("Let try that again...")
End If
The problem was caused because 500 divided by 2 is 250, divided by 5 is 50 ... and then the program continued on by dividing by 6 instead of attempting to divide by 5 again. Once var reached 10, number became 5 and no further divisions ever allowed it to reach 1 - thus an infinite loop was created.
By changing
If result = Int(result) Then
lst1.Items.Add(var)
number = result
End If
var = var + 1
to
If result = Int(result) Then
lst1.Items.Add(var)
number = result
Else
var = var + 1
End If
it correctly made multiple divisions by the same prime factor when necessary.
I'm working on a scorecard at work which has columns representing 4 possible outcomes, for example:
Successful,
unsuccessful,
Exceptional,
Other
Each staff member is assessed 5 times in the month against those ratings. So 1 person might have 3 successful, 2 exceptional, 0 unsuccessful, 0 other.
So the max instances of each outcome is 5 but the total sum of instances can't be more than 5.
I could try to type out all the combinations (and get them wrong) - is there any function/formula/VBA that anyone knows of that will list out all of the possible combinations of outcomes for me?
e.g. 5000,4100,4010,4001,3200,3020,3002,3110,3011, etc...
Since your numbers can range from 0005 to 5000, you could just write a simple loop that tests each number to see if the digits total 5:
Sub GetPermutations()
Dim i As Long
For i = 5 To 5000
If SumDigits(i) = 5 Then Debug.Print Format$(i, "0000")
Next
End Sub
Function SumDigits(s As Variant) As Long
Dim i As Long
For i = 1 To Len(s)
SumDigits = SumDigits + CLng(Mid$(s, i, 1))
Next
End Function
Alternatively:
Dim w As Long, x As Long, y As Long, z As Long
For w = 0 To 5
For x = 0 To 5
For y = 0 To 5
For z = 0 To 5
If w + x + y + z = 5 Then Debug.Print w & x & y & z
Next
Next
Next
Next
c#:
// numbering 1 to 4 - i.e.
// 1 sucessful, 2 unsucessful, 3 exception, 4 other
for(int i=1;i<4;i++)
{
for(int n=1;n<4;n++)
{
for(int d=1;d<4;d++)
{
for(int q=1;q<4;q++)
{
if(i+d+n+q<=5)
Console.WriteLine(i+n+d+q+", ");
}
}
}
}
EDIT: just saw you asked for vba:
For number1 As Integer = 1 To 4 Step 1
For number2 As Integer = 1 To 4 Step 1
For number3 As Integer = 1 To 4 Step 1
For number4 As Integer = 1 To 4 Step 1
if(number1+number2+number3+number4<=5) Then
Debug.WriteLine(number1.ToString & number2.toString &number3.toString &number4.ToString & ",");
End If
Next number4
Next number3
Next number2
Next number1
The most simple solution I could think of, there's probably better though.
Thanks for your help everyone - i managed to use a combination of suggestions by starting with the number 1, auto-filling down to 5000, then "text to columns", fixed width to separate the digits, sum to 5, filter and hey presto! Seems to have produced the right number of possible combinations adding up to 5.
Thanks again for your help!
So my professor gave me a challenge to build a decoder that could break his special formula. It was described to be 32 characters in length, alphanumeric numeric when entered but then "it has a system... the first 106 bits must be 50% 1's and the rest 0's, the remaining 22 bits are basically a hash of the previous bits so that the key can be checked..." were his exact words. Sounds to me like a 128 bit encryption with a twist. I found the below but I need VB2010 or VS2010, this says php.
<?php
function string_random($characters, $length)
{
$string = '';
for ($max = mb_strlen($characters) - 1, $i = 0; $i < $length; ++ $i)
{
$string .= mb_substr($characters, mt_rand(0, $max), 1);
}
return $string;
}
// 128 bits is 16 bytes; 2 hex digits to represent each byte
$random_128_bit_hex = string_random('0123456789abcdef', 32);
// $random_128_bit_hex might be: '4374e7bb02ae5d5bc6d0d85af78aa2ce'
Would that work? Or does it need converting? Please help. Oh and thank you :)
I wasn't promised extra credit but either way I would like to surprise him.
So the first 106 bit are 26 character and the first half of the 27.
You have first of all encode somehow the number of 0 and 1, while building the string you need to keep an eye to the number. An idea would be to build a map like this:
0 = 0000 = -4
1 = 0001 = -2
2 = 0010 = -2
3 = 0011 = 0
4 = -2
5 = 0
6 = 0
7 = +2
8 = -2
9 = 0
a = 0
b = +2
c = 0
d = +2
e = +2
f = +4
then everytime you extract a new random number you check the number associated to it and add it to a variable
balanceOfOneAndZero
your objective is have balanceOfOneAndZero = 0 when you hit your 27th character.
to do that you need a control function, that takes current balanceOfOneAndZero, the proposed character proposedChar, and current string lenght currLenght.
Would be better to split the problem into two part. First is reaching the 26th character of the sequence with balanceOfOneAndZero between -2 and 2. Any other value is not acceptable, because your 27th character can have maximum two 1 or two 0 to completely balance the first 106 characters.
so your function should do something like (I'll write in sort of pseudo code since I don't have an IDE right now)
function checkNextLetter(Dim balanceOfOneAndZero As Integer, Dim proposedChar As Char,
Dim currentLenght as Integer) As Boolean
If( ((26 - currentLenght - 1) * 4 + 2) < MOD(Map.ValueOf(proposedChar) + balanceOfOneAndZero) ) Then
Return true
Else
Return false
ENd If
End function
This function basically check if accepting the new character will still make possible to Balance the number of 0 and 1 before the 26th character.
So your main function should have a loop every time it propose a new character, something like
proposedChar = new RandomChar
While (Not checkNextLetter(balanceOfOneAndZero, proposedChar, len(currentString))
proposedChar = new RandomChar
End While
currentString = currentString & proposedChar
this only until you hit the 26th character.
Than you have to check balanceOfOneAndZero, if its 2 you add a character that begin with 00, if it's 0 you can either have 10 or 01, if it's -2 you have to add a character that begin with 11.
After this I can't help you about the rest 22 character, since there are not enough information. You could brute force the rest
EDIT:
so to brute force the rest (il start from when you reach the 26th character):
Dim stringa1, stringa2, stringa3, stringa4 As String
If balanceOfOneAndZero = 2 Then
stringa1 = currentString & '0'
stringa2 = currentString & '1'
stringa3 = currentString & '2'
stringa4 = currentString & '3'
ELse If balanceOfOneAndZero = 0 Then
stringa1 = currentString & '4'
stringa2 = currentString & '5'
stringa3 = currentString & '6'
stringa4 = currentString & '7'
Else
stringa1 = currentString & 'c'
stringa2 = currentString & 'd'
stringa3 = currentString & 'e'
stringa4 = currentString & 'f'
End if
Function GenerateAllCombination(ByVal iLenght As Integer)
Dim arrayLista As New List(Of String)()
Dim arraySubLista As New List(Of String)()
If (iLenght > 1) Then
arraySubLista = GenerateAllCombination(iLenght -1)
for each objString As String in arraySubLista
for each ele As String in arrayValori
arrayLista.add(objString & ele)
loop
loop
Else
for each ele As String in arrayValori
arrayLista.add(ele)
loop
End If
End Function
Now if you use generateAllCombination you will have a List of string with ALL the combination of 5 character.
Now you just create 4 list by concatenating those combination with your string1 to string4 (string1 & combination) etc..
put all those result on a List of string, and you have 100% that at least ONE of the string will break your teacher code
I forgot, arrayValori must be a List with all values from "0" to "f"
So I'm developing a minesweeper game and im assigning the mines, but i'm unable to create a algorithm to stop a mine to go to a place where there's already a mine, here's what i have so far:
Public Sub initflags()
Dim line, column As Integer
For line = 0 To 9
For column = 0 To 9
mat(line, column) = 0
Next
Next
Dim numbandeiras As Integer
Dim r, c As Integer
Do Until numbandeiras = 34
Randomize()
line = Int(Rnd() * 10)
column = Int(Rnd() * 10)
r = line
c = column
If r And c = 1 Then
mat(line, column) = 0
Else
numbandeiras = numbandeiras + 1
Call avisinhos()
mat(line, column) = 1
End If
Loop
End Sub
Could someone help me?
Best regards, joao.
The simplest thing to do is to check before setting, e.g:
if mat(line, column) = 0 then
numbandeiras = numbandeiras + 1
avisinhos()
mat(line, column) = 1
end if
You need to store all placed "mines" in an array of some sort. This is better in the end if you want to do something with those mines. If you have mines as objects it makes them even better for now they can have states like dead, alive or "?" like MS version.
Just my 2 cents.