/// <summary> /// Constructor. /// </summary> /// <param name="solver">The root class.</param> public TspSolver(DvrpSolver solver) { _distances = solver._distances; _depotDistances = solver._depotDistances; _dvrpProblem = solver._dvrpProblem; _visited = new bool[_dvrpProblem.Requests.Length]; }
/// <summary> /// Divide the problem into partial problems. /// </summary> /// <param name="dvrpProblem">The problem instance to divide.</param> /// <param name="numberOfParts">How many parts to divide into.</param> /// <returns>Output partial problems.</returns> public DvrpPartialProblem[] Divide(DvrpProblem dvrpProblem, int numberOfParts) { // we generate all the partitions // set {{0 0 0 0 0}} represents {{0 1 2 3 4}} // set {{0 1 2 3 4}} represents {{0}{1}{2}{3}{4}} // set {{0 1 2 1 2}} represents {{0}{1 3}{2 4}} // part - current partition // max[i] = Max{max[i-1], part[i-1]} // max[0] = -1 // example: // 0 0 0 // 0 0 1 // 0 1 0 // 0 1 1 // 0 1 2 if (numberOfParts < 1) throw new ArgumentOutOfRangeException("numberOfParts"); var n = dvrpProblem.Requests.Length; var part = new int[n]; var max = new int[n]; var maxNumberofSets = TriangularMethodBellNumber(n); var numberOfSetsForThread = maxNumberofSets/(ulong) numberOfParts; var result = new DvrpPartialProblem[numberOfParts]; var solver = new DvrpSolver(dvrpProblem); var approximateResult = solver.SolveApproximately(); for (var i = n - 2; i > -1; --i) part[i] = 0; part[n - 1] = max[0] = -1; var partLast = (int[]) part.Clone(); ulong j = 0; var k = 0; do { // checking if max[i] == Max{max[i-1], part[i-1]} for (var i = 1; i < n; ++i) { if (max[i - 1] < part[i - 1]) max[i] = part[i - 1]; else max[i] = max[i - 1]; } // we check if the last elements of the set are in their current maximum // for example // 01200345 p = 7 // 01200340 p = 6 // 01200300 p = 5 // 01200000 p = 4 // and now we can increment element for after following loop // 01201000 var p = n - 1; while (part[p] == max[p] + 1) { part[p] = 0; p = p - 1; } #region optimalization // now it is (n^2) insted of (B*n) if (p <= n - 2 && p > 1 && CheckZeros(part, p, n)) { var tmp = CalculateCombinations(max[p], p, n); if (tmp > numberOfSetsForThread - j - 1) { part[p] = part[p] + 1; ++j; } else { part[p] = max[p] + 1; for (var i = p + 1; i < n; i++) { part[i] = part[i - 1] + 1; } j += tmp; } } else if (p == n - 1 && part[p] == 0) { var tmp = (int) Math.Min(numberOfSetsForThread - j, (double) max[p] + 1); part[p] = tmp; j += (ulong) part[p]; } else { part[p] = part[p] + 1; ++j; } #endregion if (j == numberOfSetsForThread) { result[k] = new DvrpPartialProblem(partLast, approximateResult, j, part); partLast = (int[]) part.Clone(); ++k; j = 0; if (k == numberOfParts - 1) { break; } } // ReSharper disable once LoopVariableIsNeverChangedInsideLoop } while (part[n - 1] != n - 1); for (var i = 0; i < n; i++) { part[i] = i; } result[k] = new DvrpPartialProblem(partLast, approximateResult, maxNumberofSets - (ulong) k*numberOfSetsForThread, part); return result; }
/// <summary> /// Divide the problem into partial problems. /// </summary> /// <param name="dvrpProblem">The problem instance to divide.</param> /// <param name="numberOfParts">How many parts to divide into.</param> /// <returns>Output partial problems.</returns> public DvrpPartialProblem[] Divide(DvrpProblem dvrpProblem, int numberOfParts) { // we generate all the partitions // set {{0 0 0 0 0}} represents {{0 1 2 3 4}} // set {{0 1 2 3 4}} represents {{0}{1}{2}{3}{4}} // set {{0 1 2 1 2}} represents {{0}{1 3}{2 4}} // part - current partition // max[i] = Max{max[i-1], part[i-1]} // max[0] = -1 // example: // 0 0 0 // 0 0 1 // 0 1 0 // 0 1 1 // 0 1 2 if (numberOfParts < 1) { throw new ArgumentOutOfRangeException("numberOfParts"); } var n = dvrpProblem.Requests.Length; var part = new int[n]; var max = new int[n]; var maxNumberofSets = TriangularMethodBellNumber(n); var numberOfSetsForThread = maxNumberofSets / (ulong)numberOfParts; var result = new DvrpPartialProblem[numberOfParts]; var solver = new DvrpSolver(dvrpProblem); var approximateResult = solver.SolveApproximately(); for (var i = n - 2; i > -1; --i) { part[i] = 0; } part[n - 1] = max[0] = -1; var partLast = (int[])part.Clone(); ulong j = 0; var k = 0; do { // checking if max[i] == Max{max[i-1], part[i-1]} for (var i = 1; i < n; ++i) { if (max[i - 1] < part[i - 1]) { max[i] = part[i - 1]; } else { max[i] = max[i - 1]; } } // we check if the last elements of the set are in their current maximum // for example // 01200345 p = 7 // 01200340 p = 6 // 01200300 p = 5 // 01200000 p = 4 // and now we can increment element for after following loop // 01201000 var p = n - 1; while (part[p] == max[p] + 1) { part[p] = 0; p = p - 1; } #region optimalization // now it is (n^2) insted of (B*n) if (p <= n - 2 && p > 1 && CheckZeros(part, p, n)) { var tmp = CalculateCombinations(max[p], p, n); if (tmp > numberOfSetsForThread - j - 1) { part[p] = part[p] + 1; ++j; } else { part[p] = max[p] + 1; for (var i = p + 1; i < n; i++) { part[i] = part[i - 1] + 1; } j += tmp; } } else if (p == n - 1 && part[p] == 0) { var tmp = (int)Math.Min(numberOfSetsForThread - j, (double)max[p] + 1); part[p] = tmp; j += (ulong)part[p]; } else { part[p] = part[p] + 1; ++j; } #endregion if (j == numberOfSetsForThread) { result[k] = new DvrpPartialProblem(partLast, approximateResult, j, part); partLast = (int[])part.Clone(); ++k; j = 0; if (k == numberOfParts - 1) { break; } } // ReSharper disable once LoopVariableIsNeverChangedInsideLoop } while (part[n - 1] != n - 1); for (var i = 0; i < n; i++) { part[i] = i; } result[k] = new DvrpPartialProblem(partLast, approximateResult, maxNumberofSets - (ulong)k * numberOfSetsForThread, part); return(result); }
/// <summary> /// Solve a partial problem with a given timeout. /// </summary> /// <param name="partialData">Binary serialized DVRP partial problem data.</param> /// <param name="timeout">Maximum time for computations.</param> /// <returns>Binary serialized solution.</returns> public override byte[] Solve(byte[] partialData, TimeSpan timeout) { try { DvrpPartialProblem problem; using (var memoryStream = new MemoryStream(partialData)) { problem = (DvrpPartialProblem) _formatter.Deserialize(memoryStream); } var solver = new DvrpSolver(_dvrpProblem); using (var memoryStream = new MemoryStream()) { _formatter.Serialize(memoryStream, solver.Solve(problem, timeout)); State = solver.State; return memoryStream.ToArray(); } } catch (Exception ex) { Exception = ex; State = TaskSolverState.Error; return null; } }
/// <summary> /// Constructor. /// </summary> /// <param name="solver">The root class.</param> public TspSolver(DvrpSolver solver) { _distances = solver._distances; _depotDistances = solver._depotDistances; _dvrpProblem = solver._dvrpProblem; _visited = new bool[_dvrpProblem.Requests.Length]; }