private void TopSortInternal(List <Pip> pips, List <List <Pip> > sortedPipGroups)
{
var childrenLeftToVisit = new Dictionary <Pip, int>();
sortedPipGroups.Add(new List <Pip>());
int totalAdded = 0;
foreach (var pip in pips)
{
childrenLeftToVisit[pip] = 0;
}
foreach (var pip in pips)
{
foreach (var dependent in m_pipGraph.RetrievePipImmediateDependents(pip) ?? Enumerable.Empty <Pip>())
{
childrenLeftToVisit[dependent]++;
}
}
foreach (var pip in pips)
{
if (childrenLeftToVisit[pip] == 0)
{
totalAdded++;
sortedPipGroups[sortedPipGroups.Count - 1].Add(pip);
}
}
int currentLevel = sortedPipGroups.Count - 1;
while (totalAdded < pips.Count)
{
sortedPipGroups.Add(new List <Pip>());
foreach (var pip in sortedPipGroups[currentLevel])
{
foreach (var dependent in m_pipGraph.RetrievePipImmediateDependents(pip) ?? Enumerable.Empty <Pip>())
{
if (--childrenLeftToVisit[dependent] == 0)
{
totalAdded++;
sortedPipGroups[currentLevel + 1].Add(dependent);
}
}
}
currentLevel++;
}
}
