private State DeleteEdges(State state, int row, int col)
{
state.GetCityTo()[row] = col;
state.GetCityFrom()[col] = row;
state.SetCitiesInSolution(state.GetCitiesInSolution() + 1);
if (state.GetCitiesInSolution() < _cities.Length - 1)
{
int start = row;
int end = col;
while (state.GetCityFrom()[start] != -1)
{
start = state.GetCityFrom()[start];
}
while (state.GetCityTo()[end] != -1)
{
end = state.GetCityTo()[end];
}
while (start != col)
{
state.Matrix.GetMatrix()[end, start] = double.PositiveInfinity;
state.Matrix.GetMatrix()[col, start] = double.PositiveInfinity;
start = state.GetCityTo()[start];
}
}
return(state);
}
// Simply used for generating the results of the solution.
private PathCalculation GeneratePathResult(State solution, City[] cities, double elapsedTime)
{
if (solution == null)
{
return(new PathCalculation(null, elapsedTime, bssfUpdates));
}
List <City> pathResult = new List <City>();
int currentCity = solution.GetCityTo()[0];
while (pathResult.Count < cities.Length)
{
pathResult.Add(cities[currentCity]);
currentCity = solution.GetCityTo()[currentCity];
}
return(new PathCalculation(pathResult.ToArray(), elapsedTime, bssfUpdates));
}
private void PrintMatrix(State state)
{
Console.WriteLine("------------------------------------");
Matrix matrix = state.Matrix;
for (int i = 0; i < state.GetCityTo().Length; i++)
{
Console.WriteLine(i + " --> " + state.GetCityTo()[i]);
}
Console.WriteLine("------------------------------------");
for (int i = 0; i < matrix.GetMatrix().GetLength(0); i++)
{
for (int j = 0; j < matrix.GetMatrix().GetLength(0); j++)
{
Console.Write((Double.IsPositiveInfinity(matrix.GetMatrix()[i, j]) ? "INF" : matrix.GetMatrix()[i, j].ToString()) + "\t");
}
Console.Write("\n");
}
}
private State GenerateReducedMatrix(State state)
{
Matrix matrix = state.Matrix;
// This is the total cost of reduction.
double sumDifference = 0;
// Reduce row by row
for (int i = 0; i < matrix.GetMatrix().GetLength(0); i++)
{
// Only reduce the row if a cell in this row has NOT already been select as part of the path.
if (state.GetCityTo()[i] == -1)
{
double rowMin = double.PositiveInfinity;
for (int j = 0; j < matrix.GetMatrix().GetLength(0); j++)
{
if (matrix.GetMatrix()[i, j] < rowMin)
{
rowMin = matrix.GetMatrix()[i, j];
}
}
if (!double.IsInfinity(rowMin))
{
for (int j = 0; j < matrix.GetMatrix().GetLength(0); j++)
{
matrix.GetMatrix()[i, j] -= rowMin;
}
}
sumDifference += rowMin;
}
}
// Reduce column by column
for (int i = 0; i < matrix.GetMatrix().GetLength(0); i++)
{
// Only reduce the col if a cell in this col has NOT already been select as part of the path.
if (state.GetCityFrom()[i] == -1)
{
double colMin = double.PositiveInfinity;
for (int j = 0; j < matrix.GetMatrix().GetLength(0); j++)
{
if (matrix.GetMatrix()[j, i] < colMin)
{
colMin = matrix.GetMatrix()[j, i];
}
}
if (!double.IsInfinity(colMin))
{
for (int j = 0; j < matrix.GetMatrix().GetLength(0); j++)
{
matrix.GetMatrix()[j, i] -= colMin;
}
}
sumDifference += colMin;
}
}
state.LowerBound += sumDifference;
state.Matrix = matrix;
return(state);
}
