grbfsm.cpp

数据结构与算法分析（C++）（版第二版）源码

#include <iostream.h>
#include <stdlib.h>

#include "book.h"

#include "grmat.h"

#include "aqueue.h"

void PreVisit(Graph* G, int v) {
  cout << "PreVisit vertex " << v << "\n";
}

void PostVisit(Graph* G, int v) {
  cout << "PostVisit vertex " << v << "\n";
}

void BFS(Graph* G, int start, Queue<int>* Q) {
  int v, w;
  Q->enqueue(start);         // Initialize Q
  G->setMark(start, VISITED);
  while (Q->length() != 0) { // Process all vertices on Q
    Q->dequeue(v);
    PreVisit(G, v);          // Take appropriate action
    for (w=G->first(v); w<G->n(); w = G->next(v,w))
      if (G->getMark(w) == UNVISITED) {
        G->setMark(w, VISITED);
        Q->enqueue(w);
      }
    PostVisit(G, v);         // Take appropriate action
  }
}

// Test Depth First Search:
// Version for Adjancency Matrix representation
main(int argc, char** argv) {
  Graph* G;
  FILE *fid;

  if (argc != 2) {
    cout << "Usage: grdfsm <file>\n";
    exit(-1);
  }

  if ((fid = fopen(argv[1], "rt")) == NULL) {
    cout << "Unable to open file |" << argv[1] << "|\n";
    exit(-1);
  }

  G = createGraph<Graphm>(fid);
  if (G == NULL) {
    cout << "Unable to create graph\n";
    exit(-1);
  }

  Queue<int>* Q = new AQueue<int>(G->n());

  BFS(G, 0, Q);
  return 0;
}