public SearchResults(long numLeafsCreated, long numSolutionsFound,
InvasionSolution defaultSolution,
InvasionSolution optimizedSolution)
{
SearchTimeSeconds = -1;
NumLeafsCreated = numLeafsCreated;
NumSolutionsFound = numSolutionsFound;
DefaultSolution = defaultSolution;
OptimizedSolution = optimizedSolution;
}
/*
* Driver for search logic.
* i) Check if the chosen state is solved, and if so update solution records accordiningly
* ii) If not solved, check for preliminary qualities that would disqualify this sub problem from being searched
* iii) If not disqualified, run a recursive division on the invading army into all possible invasion groupings
* Each combination found will be added as a new leaf on the tree
*/
public void Search(SearchState chosenState, bool keepArmyTogether)
{
if (chosenState.IsSolved)
{
mNumLeafsCreated++;
#region SolutionFound
// Check if the solution is relevant depending on which optimizations are being used and solution quality
bool updateSolution = false;
bool recordSolution = false;
int numStepsInInvasion = chosenState.Depth;
if (mBestSolution == null) // havent found a solution yet
{
recordSolution = updateSolution = true;
if (mIsOptimized)
{
// only accept solutions that occur in as many turns as the new solution
mMaxDepthOfTree = numStepsInInvasion;
}
}
else if (numStepsInInvasion < mBestSolutionDepth) // found a quicker invasion strategy
{
recordSolution = updateSolution = true;
mBestSolution = null;
// reset solution tracking
if (mIsOptimized)
{
mNumSolutionsFound = 0;
mMaxDepthOfTree = numStepsInInvasion;
}
}
else if (mBestSolutionDepth == numStepsInInvasion) // occurs in the same number of turns as previous solutions
{
recordSolution = true;
if (chosenState.Prob.InvadingArmy.CalculateArmyValue() > mBestSolutionArmyValue)
{
updateSolution = true;
}
}
else // worse quality of solution
{
recordSolution = !mIsOptimized;
}
if (recordSolution)
{
mNumSolutionsFound++;
}
// Create and store new solution
if (updateSolution)
{
mBestSolution = ToSolution(chosenState, mInitialArmy, mInitialNation);
mBestSolutionDepth = numStepsInInvasion;
mBestSolutionArmyValue = chosenState.Prob.InvadingArmy.CalculateArmyValue();
}
#endregion
}
else // sub problem is not solved. Check if sub problem can be divided
{
if (mBestSolution == null) // record partial solutions until an actual solution is found
{
if (mBestPartialSolution == null)
{
mBestPartialSolution = chosenState;
mBestPartialSolutionValue = chosenState.Prob.ProblemValue;
}
else
{
// only update partial solution if it was able to take more cities than the previous, regardless of better army value
if (chosenState.Prob.NationBlueprint.NumCitiesRemaining < mBestPartialSolution.Prob.NationBlueprint.NumCitiesRemaining)
{
float probValue = chosenState.Prob.ProblemValue;
if (probValue < mBestPartialSolutionValue)
{
mBestPartialSolution = chosenState;
mBestPartialSolutionValue = probValue;
}
}
}
}
// check for disqualifying features of invasion state
bool validState = true;
if (chosenState.ParentProblem != null)
{
if (chosenState.ParentProblem.StateValue == chosenState.StateValue) // army did not heal nor was a city taken
{
// do nothing, this state didn't progress the invasion
validState = false;
}
}
// took more turns to complete than our max turn limit
if (mMaxDepthOfTree != -1 && mIsOptimized && chosenState.Depth >= mMaxDepthOfTree)
{
validState = false;
}
// valid subproblem. Add all new leafs possible from this state
if (validState)
{
List <SearchState> subProblems = Fdiv(chosenState, keepArmyTogether);
mNumLeafsCreated += subProblems.Count;
foreach (SearchState subProblem in subProblems)
{
mOpenLeafs.AddLast(subProblem);
}
}
else
{
mNumLeafsCreated++;
}
}
}
public SearchResults SearchForSolutions(ArmyBlueprint attackers, NationBlueprint defenders, bool optimize)
{
mInitialArmy = attackers;
mInitialNation = defenders;
mIsOptimized = true; /* = optimize; Replace after data collection*/
// Initialize start variables and start invasion search
SearchState initialState = new SearchState(attackers, defenders, 0, null, null);
mOpenLeafs.Clear();
// orrient the nations layout relative to the army. TODO: allow for dynamic invasion direction
initialState.Prob.NationBlueprint.BeginInvasion(Vector2.right);
// Do the default search keeping the units together
mOpenLeafs.AddLast(initialState);
mPruneSolutions = true; // only care about the best solution with army grouped up. Only record
mMaxDepthOfTree = mBestSolutionDepth = -1; // max depth = -1 until a solution is found creating a limit to depth
// Search for solutions with linear invasion strategy
while (mOpenLeafs.Count > 0)
{
SearchState pop = mOpenLeafs.Last.Value;
mOpenLeafs.RemoveLast();
Search(pop, true);
}
// record default invasion stats
InvasionSolution linearSolution = null;
if (mBestSolution == null) // no solution was found
{
// record the best result possible
linearSolution = ToSolution(mBestPartialSolution, mInitialArmy, mInitialNation);
}
else
{
linearSolution = mBestSolution;
}
int bestLinearDepth = linearSolution != null ? mBestSolutionDepth : -1;
// update the max depth of the optimized search to be the depth of the default time
mMaxDepthOfTree = bestLinearDepth;
//Debug.Log("Best Case Group Scenario took " + mMaxDepthOfTree + " turns to complete, needing " + (mMaxDepthOfTree - initialState.Prob.NationBlueprint.NumCitiesRemaining) + " turns to heal");
// reset search variables for the optimized search
mPruneSolutions = optimize;
mOpenLeafs.Clear();
mBestSolution = null;
mBestPartialSolution = null;
mOpenLeafs.AddLast(initialState);
// search for parallel attack strategy solutions
while (mOpenLeafs.Count > 0)
{
SearchState pop = mOpenLeafs.Last.Value;
mOpenLeafs.RemoveLast();
Search(pop, false);
}
// Record optimized Solution
InvasionSolution parallelSolution = null;
if (mBestSolution == null)
{
parallelSolution = ToSolution(mBestPartialSolution, mInitialArmy, mInitialNation);
}
else
{
parallelSolution = mBestSolution;
}
int bestOptimizedDepth = parallelSolution != null ? mBestSolutionDepth : -1;
return(new SearchResults(mNumLeafsCreated, mNumSolutionsFound,
linearSolution, parallelSolution));
}