Shuffling Algorithim

[3XXXDDD]

Just curious what the shuffling algorithm is in LackeyCCG, is it something simple like List_Shuffle or is it more than that like Fisher-Yates?

[Trevor]

Here it is:
      

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int *PositionsArray = new int [GetNumEntries()];
if(PositionsArray==NULL)
return;

for(int i=0; i<GetNumEntries(); i++)
PositionsArray[i]=i;

RandomizeArray(GetNumEntries(),PositionsArray);

ItemClass *TempEntries = new ItemClass[GetNumEntries()];
for(int i=0; i<GetNumEntries(); i++)
TempEntries[i].Set(Entries[i]);

for(int i=0; i<GetNumEntries(); i++)
Entries[i].Set(TempEntries[PositionsArray[i]]);

if(TempEntries)
delete [] TempEntries;
TempEntries=NULL;
if(PositionsArray!=NULL)
delete [] PositionsArray;
PositionsArray=NULL;

Code Select Expand

void RandomizeArray(int ArrayLength,int Array[])
{
if(ArrayLength==0)
return;
int *TempData = new int [ArrayLength];
if(TempData==NULL)
return;
int CurrentLength=0;
for(int i=0; i<ArrayLength; i++) // COPY ARRAY to TEMPARRAY
TempData[i]=Array[i];
int Pos=0;
CurrentLength=ArrayLength;
for(int i=0; i<ArrayLength; i++)
{
Pos=GenerateRandomNumber(0,CurrentLength-1); // randomly choose a position in those that remain
Array[i]=TempData[Pos]; //  copy it
for(int j=Pos; j<CurrentLength-1; j++)
TempData[j]=TempData[j+1];
CurrentLength--;  // Then remove the one you just picked from the array
}
DeleteTempData
}


Code Select Expand

int GenerateRandomNumber(int LowerInt, int UpperInt)
{
if(LowerInt==UpperInt)//If there is only one option, just return that
return LowerInt;
if(LowerInt>UpperInt)//This section assures that lower number is indeed lower
{
int TempInt=LowerInt;
LowerInt=UpperInt;
UpperInt=TempInt;
}
long int TempResult=rand();
int Result = TempResult % (UpperInt - LowerInt + 1) + LowerInt;
return Result;
}
I wrote it a while ago, and I might do things differently now, but I believe it works as intended.

[Alastair]

For future reference Trevor or anybody really, if you need to show code in the forum don't use quote, use the code button (looks like a # symbol). It ignores forum shortcuts.