当前位置: 首页>>代码示例>>C++>>正文


C++ ListGraph::runningNode方法代码示例

本文整理汇总了C++中ListGraph::runningNode方法的典型用法代码示例。如果您正苦于以下问题:C++ ListGraph::runningNode方法的具体用法?C++ ListGraph::runningNode怎么用?C++ ListGraph::runningNode使用的例子?那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在ListGraph的用法示例。


在下文中一共展示了ListGraph::runningNode方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C++代码示例。

示例1: solver

int
HeuristicGroupTSP(ListGraph &g,  ListGraph::EdgeMap<double>& weights, vector<
                  set<ListGraph::Node> > &S, vector<ListGraph::Node> &sol, long
                  max_time,  double &best_time,  double &LB, string &alg_info)
{
  /**
   * Computa solucao heuristica para o Group TSP.
   *
   * Entrada:
   * @param   g           grafo simples utilizado
   * @param   weights     pesos das arestas
   * @param   S           vetor de grupos de vertices (ver def. do problema)
   * @param   max_time    tempo maximo (em seg) que o procedimento deve ocorrer
   *
   * Saida:
   * @param   sol         sequencia de vertices que representa ciclo
   * @param   best_time   momento em que solucao atual foi encontrada
   * @param   LB          limite inferior encontrado para custo otimo
   * @param   alg_info    informacoes de execucao do algoritmo, ex: cadeia de
   *                      heuristicas utilizadas
   *
   * @return          0 = nao foi possivel encontrar solucao
   *                  1 = solucao encontrada, mas nao necessariamente otima
   *                  2 = solucao otima encontrada
   */

  // Sample Algorithm
  // Until solution is not integral, sets highest variable to its closest
  // integer value.

  // Variables
  GroupTSPLPSolver::ReturnType rettype = GroupTSPLPSolver::OPTIMAL_FRACTIONARY;
  GroupTSPLPSolver solver(g, weights, S);
  ListGraph::NodeMap<double> lpsol_vertex(g);
  ListGraph::EdgeMap<double> lpsol_edge(g);
  ListGraph::NodeMap<bool> already_set(g, false);
  double objVal = 0;
  time_t start = time(NULL);

  LB = -1;

  // main loop
  cout << "STARTING\n";
  while (rettype == GroupTSPLPSolver::OPTIMAL_FRACTIONARY) {
    cout << "Solving..\n";
    rettype = solver.getSolution(lpsol_vertex, lpsol_edge, objVal);

    if (fabsl(LB - (-1)) < EPS) {
      LB = objVal;
    }


    if (rettype == GroupTSPLPSolver::OPTIMAL_FRACTIONARY) {
      // Round highest variable to closest value.
      double mx = -1;
      Node mx_idx=INVALID;

      for(NodeIt v(g); v!=INVALID; ++v) {
        if (!already_set[v]) {
          if (lpsol_vertex[v] > mx) {
            mx = lpsol_vertex[v];
            mx_idx = v;
          }
        }
      }

      if (mx_idx != INVALID) {
        // int val = (lpsol_vertex[mx_idx] > 0.5 ? 1 : 0);
        int val = calculateIntegralWithProportionalProbability(lpsol_vertex[mx_idx]);
        cout << "Fixing " << g.id(mx_idx) << " to " << val << "\n";
        solver.fixNodeVariable(mx_idx, val);
        already_set[mx_idx] = true;
      } else {
        // it seems we were unable to obtain a solution with integral x[e]
        break;
      }
    }
  }

  // OBTAIN SOLUTION
  best_time = time(NULL) - start;
  if (rettype != GroupTSPLPSolver::OPTIMAL_INTEGRAL) {
    return 0;
  } else {
    /* do dfs to find out the answer */
    ListGraph::NodeMap<bool> vis(g, false);

    for(ListGraph::NodeIt v(g); v != INVALID; ++v) {
      if ( lpsol_vertex[v] > 1.0 - EPS ) {
        queue<ListGraph::Node> q;
        vis[v] = true;
        q.push(v);

        while (!q.empty()) {
          ListGraph::Node u = q.front(); q.pop();
          sol.push_back(u);

          for(ListGraph::IncEdgeIt e(g, u); e != INVALID; ++e) {
            ListGraph::Node w = g.runningNode(e);
            if (lpsol_edge[e] > 1.0 - EPS && !vis[w]) {
//.........这里部分代码省略.........
开发者ID:nmizoguchi,项目名称:mc658-lab7,代码行数:101,代码来源:group_tsp.cpp


注:本文中的ListGraph::runningNode方法示例由纯净天空整理自Github/MSDocs等开源代码及文档管理平台,相关代码片段筛选自各路编程大神贡献的开源项目,源码版权归原作者所有,传播和使用请参考对应项目的License;未经允许,请勿转载。