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912-notes/thu_dsa/chp6/Graph.h

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3.5 KiB
C++

#ifndef GRAPH_H_
#define GRAPH_H_
#include "../chp2/Vector.h"
#include "../chp4/Stack.h"
#include "../chp4/Queue.h"
typedef enum { UNDISCOVERED, DISCOVERED, VISITED } VStatus;
typedef enum { UNDETERMINED, TREE, BACKWARD, FORWARD, CROSS } Etype;
//abstract class Graph
template <typename Tv, typename Te>
class Graph{
private:
void reset(); //reset all information of all vertices and edges
void BFS(int, int&);
void DFS(int, int&);
void BCC(int, int&, Stack<int>&);
bool TSort(int, int&, Stack<Tv>*);
template <typename PU> void PFS(int, PU);
public:
int num_of_vertices;
int num_of_edges;
//vertex methods
virtual int insertVertex(Tv const&) = 0; //return the id number of the new vertex
virtual Tv removeVertex(int) = 0;
virtual Tv& vertex(int) = 0;
virtual int inDegree(int) = 0;
virtual int outDegree(int) = 0;
virtual int firstNeighbor(int) = 0;
virtual int nextNeighbor(int, int) = 0;
virtual int& dtime(int) = 0;
virtual int& ftime(int) = 0;
virtual int& parent(int) = 0;
virtual int& priority(int) = 0;
virtual VStatus& status(int) = 0;
//directed egde methods
virtual bool exists(int, int) = 0;
virtual void insertEdge(Te const&, double, int, int) = 0;
virtual Te removeEdge(int, int) = 0;
virtual Etype& type(int, int) = 0;
virtual Te& edge(int, int) = 0;
virtual double& weight(int, int) = 0;
//Graph related algorithms
void bfs(int);
void dfs(int);
void bcc(int);
void prim(int);
void dijkstra(int);
Stack<Tv>* tSort(int);
template <typename PU> void pfd(int, PU);
};
//private methods
template <typename Tv, typename Te>
void Graph<Tv, Te>::reset(){//reset all information of all vertices and edges
for(int ix = 0; ix != num_of_vertices; ++ix){
status(ix) = UNDISCOVERED;
priority(ix) = 0;
dtime(ix) = -1;
ftime(ix) = -1;
parent(ix) = -1;
for (int jx = 0; jx != num_of_vertices; ++jx)
if(exists(ix, jx)) type(ix, jx) = UNDETERMINED;
}
}
template <typename Tv, typename Te>
void Graph<Tv, Te>::BFS(int x, int &clock){
Queue<int> Q;
int neighbor;
Q.enqueue(x);
status(x) = DISCOVERED;
while(!Q.empty()){
x = Q.dequeue();
dtime(x) = ++clock;
for (neighbor = firstNeighbor(x); neighbor != -1; neighbor = nextNeighbor(x, neighbor)){
if (status(neighbor) == UNDISCOVERED) {
status(neighbor) = DISCOVERED;
type(x, neighbor) = TREE;
parent(neighbor) = x;
Q.enqueue(neighbor);
}
else type(x, neighbor) = CROSS;
}
status(x) = VISITED;
}
}
template <typename Tv, typename Te>
void Graph<Tv, Te>::DFS(int x, int& clock){
dtime(x) = ++clock;
status(x) = DISCOVERED;
for(int neighbor = firstNeighbor(x); neighbor != -1; neighbor = nextNeighbor(x, neighbor)){
switch(status(neighbor)){
case UNDISCOVERED:
type(x, neighbor) = TREE;
parent(neighbor) = x;
DFS(neighbor, clock);
break;
case DISCOVERED:
type(x, neighbor) = BACKWARD;
break;
case VISITED:
default:
if (dtime(x) < dtime(neighbor)) type(x, neighbor) = FORWARD;
else type(x, neighbor) = CROSS;
break;
}
}
ftime(x) = ++clock;
status(x) = VISITED;
}
//Graph related algorithms
template <typename Tv, typename Te>
void Graph<Tv, Te>::bfs(int start){
reset();
int x = start;
int clock = 0;
do {
if (status(x) == UNDISCOVERED)
BFS(x, clock);
} while ((x = ++x % num_of_vertices) != start);
}
template <typename Tv, typename Te>
void Graph<Tv, Te>::dfs(int start){
reset();
int clock = 0;
int x = start;
do{
if (status(x) == UNDISCOVERED)
DFS(x, clock);
} while ((x = ++x % num_of_vertices) != start);
}
#endif