/* Called in a background thread. Used to generate bitstrings of a specified length. These strings
* are represented as an array of bools - true = 1, false = 0. This method is more efficient.
* EX: ("11001")
*
* We use these bitstrings to represent all possible combinations of the sections (even invalid ones).
*
* @param e.Argument This value passed through the BackgroundWorker call is the length of the bitstring.
*/
private void generateAllBitStrings(object sender, DoWorkEventArgs e)
{
Dictionary<string, List<int>> classes = new Dictionary<string, List<int>>();
//Separate sections by class
int i = 0;
foreach (ClassSection section in possibleSections)
{
List<int> indices = new List<int>();
if (!classes.Keys.Contains(section.parentClass))
{
indices.Add(i);
classes.Add(section.parentClass, indices);
}
else
{
classes.TryGetValue(section.parentClass, out indices);
indices.Add(i);
}
i++;
}
//Check each class for working combinations
i = 0;
Dictionary<int, List<DepartmentClass>> groups = new Dictionary<int, List<DepartmentClass>>();
foreach (var kv in classes)
{
short n = (short)kv.Value.Count; //The length of the bitstrings
List<DepartmentClass> validClassCombinations = new List<DepartmentClass>();
List<ClassSection> sectionPool = getSectionPool(kv.Value, possibleSections);
/* Progress tracking */
double targetStringCount = Math.Pow(2, n); //This is the target number of strings to generate
double totalResults = 0;
/* Begin generating bitstrings */
bool[] first = new bool[n]; //First string is all false
for (short x= 0; x < n; x++)
{
first[x] = false;
}
bool[] intermediate = first;
List<ClassSection> firstSections = checkBitstring(first, sectionPool);
if (firstSections != null)
{
DepartmentClass temp = new DepartmentClass();
temp.sections = firstSections;
validClassCombinations.Add(temp);
}
totalResults++;
//For user-facing progress updates
currentClassRunning++;
ulong rollingTotal = 0;
short multiplier = 1;
ulong progressStep = (ulong)Math.Ceiling(targetStringCount / 100);
this.Dispatcher.BeginInvoke(delegate { progress.Value = 0; });
MyStopwatch timer = new MyStopwatch();
/* Generating loop */
do
{
//Start timing
if (rollingTotal == 0)
{
timer.start();
}
//Make the next bitstring
intermediate = generateNextBitstring(intermediate);
//Update timeleft
if (rollingTotal == Math.Pow(2, multiplier))
{
float averageTime = (float)timer.stop() / (float)Math.Pow(2, multiplier);
secondsRemaining = (int)((averageTime * (targetStringCount - totalResults)) / 1000.0);
multiplier++;
rollingTotal = 0;
}
//Update progress bar
if (totalResults % progressStep == 0)
{
this.Dispatcher.BeginInvoke(delegate { progress.Value += 1; });
}
//Increment counters
totalResults++;
rollingTotal++;
//Check the bitstring we generated
List<ClassSection> nextSections = checkBitstring(intermediate, sectionPool);
if (nextSections != null)
{
DepartmentClass temp = new DepartmentClass();
temp.sections = nextSections;
validClassCombinations.Add(temp);
}
} while (totalResults < targetStringCount);
groups.Add(i, validClassCombinations);
i++;
}
i = 1;
//Combination two classes and weed out the combinations that aren't valid
while (groups.Keys.Count > 1)
{
//Tournament!
List<DepartmentClass> champCombination = new List<DepartmentClass>();
groups.TryGetValue(0, out champCombination);
List<DepartmentClass> challengerCombination = new List<DepartmentClass>();
groups.TryGetValue(i, out challengerCombination);
List<DepartmentClass> winnersCircle = new List<DepartmentClass>();
//Fight!
foreach (DepartmentClass champ in champCombination)
{
foreach (DepartmentClass challenger in challengerCombination)
{
List<ClassSection> contender = new List<ClassSection>();
foreach (ClassSection section in champ.sections)
{
contender.Add(section);
}
foreach (ClassSection section in challenger.sections)
{
contender.Add(section);
}
if (combinationSuccessful(contender))
{
DepartmentClass success = new DepartmentClass();
success.sections = contender;
winnersCircle.Add(success);
}
}
}
groups.Remove(i);
groups.Remove(0);
groups.Add(0, winnersCircle);
i++;
}
//Prepare the confirmed classed to be displayed
List<DepartmentClass> confirmed = new List<DepartmentClass>();
groups.TryGetValue(0, out confirmed);
i = 0;
foreach (DepartmentClass parent in confirmed)
{
confirmedSections.Add(parent.sections);
}
//Report that we're done and ready for GUI update
(sender as BackgroundWorker).ReportProgress(100, null);
//Because the time remaining isn't an exact science, we cheat at the end and force the values to be where they should
// at the end.
secondsRemaining = 1;
this.Dispatcher.BeginInvoke(delegate { progress.Value = 100; });
}
/**
* Adds a list of courses to the possibility list that were picked from the class's list of sections
*
* @param sectionPool The class that contains the sections we want
* @param randCount The number of random sections to return
* @param randGen The random number generator to use. We make one if there isn't one specified
*
* @return The list of classes we picked
*/
private List<ClassSection> pickSections(DepartmentClass sectionPool, int randCount, Random randGen = null)
{
List<ClassSection> finalSections = new List<ClassSection>();
List<ClassSection> sectionsToRemove = new List<ClassSection>();
//Add classes that are not excluded to the temp pool
foreach (ClassSection section in sectionPool.sections)
{
//If course is not in exlusions
if (!section.excluded)
{
finalSections.Add(section);
}
}
for (short i = 0; i < dayLimiters.Count; i++)
{
CheckBox chkDay = dayLimiters[i];
if (chkDay.IsChecked == false) continue;
string day = convertIndexToDay(i);
Tuple<ComboBox, ComboBox> dayMaster = timeCombos[i];
string time = ((ComboBoxItem)(dayMaster.Item1.SelectedItem)).Content + " - " + ((ComboBoxItem)(dayMaster.Item2.SelectedItem)).Content;
foreach (ClassSection section in finalSections)
{
if (section.time.ToLower() == "tba" || !section.days.ToLower().Contains(day)) continue;
if (doTimesIntersect(time, section.time))
{
sectionsToRemove.Add(section);
}
}
}
//Remove the classes
foreach (ClassSection removal in sectionsToRemove)
{
finalSections.Remove(removal);
}
//Now pick random selections from what's left
if (limitRandom)
{
if (randCount >= finalSections.Count)
{
//Do nothing and add all of the final sections to the possible sections
}
else
{
if (randGen == null)
{
randGen = new Random((int)Math.Round(DateTime.Now.Ticks * 6911.0));
}
List<ClassSection> randomSections = new List<ClassSection>();
for (; randCount > 0; randCount--)
{
//Pick a number from zero to the sections count
int selection = (int)Math.Round(randGen.NextDouble()) * (finalSections.Count - 1);
//Remove the index we picked
randomSections.Add(finalSections[selection]);
finalSections.RemoveAt(selection);
}
finalSections.Clear();
foreach (ClassSection section in randomSections)
{
finalSections.Add(section);
}
}
}
return finalSections;
}
