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 程式師世界 >> 編程語言 >> C語言 >> C++ >> 關於C++ >> 圖的深度優先搜索和廣度優先搜索算法、最小生成樹兩種算法

圖的深度優先搜索和廣度優先搜索算法、最小生成樹兩種算法

編輯:關於C++

一:通用圖結構

#ifndef _GRAPH_H
#define _GRAPH_H

#include 
#include 
#include 
#include 
using namespace::std;

#define MAX_COST 0x7FFFFFFF   //花費無限大設為整型最大值

///////////////////////////////////////////////////////////////////////////////////////////
//通用圖結構
template 
class graph{
public:
	bool is_empty()const;
	bool is_full()const;
	
	int get_numvertices()const;    //當前頂點數
	int get_numedges()const;       //當前邊數
public:
	virtual bool insert_vertex(const T&) = 0;            //插入頂點
	virtual bool insert_edge(const T&, const T&, E) = 0;    //插入邊

	virtual int get_firstneighbor(const T&)const = 0;    //得到第一個鄰接頂點
	virtual int get_nextneighbor(const T&, const T&)const = 0;    //某鄰接頂點的下一個鄰接頂點
	
	virtual void print_graph()const = 0;
	virtual int get_vertex_index(const T&)const = 0;     //得到頂點序號

	virtual void depth_first(const T&) = 0;
	virtual void broad_first(const T&) = 0;

	virtual void min_spantree_kruskal() = 0;
	virtual void min_spantree_prim(const T&) = 0;
protected:
	static const int VERTICES_DEFAULT_SIZE = 10;         //默認圖頂點數
	int max_vertices;
	int num_vertices;
	int num_edges;
};

template 
bool graph::is_empty()const
{
	return num_edges == 0;
}

template 
bool graph::is_full()const
{
	return num_vertices >= max_vertices 
		   || num_edges >= max_vertices*(max_vertices-1)/2;    //判滿,分為頂點滿和邊滿
}

template 
int graph::get_numvertices()const
{
	return num_vertices;
}

template 
int graph::get_numedges()const
{
	return num_edges;
}

///////////////////////////////////////////////////////////////////////////////////////////

#define VERTICES_DEFAULT_SIZE graph::VERTICES_DEFAULT_SIZE
#define num_vertices          graph::num_vertices   
#define num_edges             graph::num_edges
#define max_vertices          graph::max_vertices         

///////////////////////////////////////////////////////////////////////////////////////////

#endif /*graph.h*/

二:鄰接矩陣圖結構

#pragma once

#include "graph.h"

//圖的鄰接矩陣表示法
template 
class graph_mtx : public graph{
public:
	graph_mtx(int);                   
	~graph_mtx();                             
public:
	bool insert_vertex(const T&);
	bool insert_edge(const T&, const T&, E);  

	int get_firstneighbor(const T&)const;
	int get_nextneighbor(const T&, const T&)const;
	
	int get_vertex_index(const T&)const;
	T& get_vertex_symbol(const int)const;
	void print_graph()const;

	void depth_first(const T&);
	void broad_first(const T&);

	void min_spantree_kruskal();
	void min_spantree_prim(const T&);
protected:
	void depth_first(const T&, bool *);
private:
	T* vertices_list;                        //頂點線性表
	E **edge;                              //內部矩陣
};

template 
graph_mtx::graph_mtx(int sz = VERTICES_DEFAULT_SIZE)
{
	max_vertices = sz > VERTICES_DEFAULT_SIZE ? sz 
									: VERTICES_DEFAULT_SIZE;
	vertices_list = new T[max_vertices];

	edge = new int*[max_vertices];                    //動態申請二維數組
	for(int i=0; i
graph_mtx::~graph_mtx()
{
	for(int i=0; i
bool graph_mtx::insert_vertex(const T& vert)
{
	if(this->is_full())                       //派生類函數調用父類函數,用this或加作用域
		return false;
	vertices_list[num_vertices++] = vert;
	return true;
}

template 
bool graph_mtx::insert_edge(const T& vert1, const T& vert2, E cost = MAX_COST)//由於權值存在默認值,get_neighbor的操作需判斷是否等於MAX_COST,否則不能正常取得鄰接頂點
{
	if(this->is_full())                       //判滿
		return false;

	int index_v1 = get_vertex_index(vert1);   //得到頂點序號
	int index_v2 = get_vertex_index(vert2);

	if(index_v1 == -1 || index_v2 == -1 )
		return false;
	
	edge[index_v1][index_v2] = edge[index_v2][index_v1] = cost;    //無向圖
	++num_edges;	
	
	return true;
}

template 
int graph_mtx::get_firstneighbor(const T& vert)const
{
	int index = get_vertex_index(vert);

	if(index != -1){
		for(int i=0; i
int graph_mtx::get_nextneighbor(const T& vert1, const T& vert2)const
{
	int index_v1 = get_vertex_index(vert1);
	int index_v2 = get_vertex_index(vert2);

	if(index_v1 != -1 && index_v2 != -1){
		for(int i=index_v2+1; i
int graph_mtx::get_vertex_index(const T& vert)const
{
	for(int i=0; i
T& graph_mtx::get_vertex_symbol(const int index)const
{
	assert(index >= 0 && index < this->get_numvertices());
	//assert(index >= 0 && index < num_vertices); //error,由於num_vertices本身是我們用宏替換父類該元素,在這裡使用會出現雙重宏
	return vertices_list[index];
}

template 
void graph_mtx::print_graph()const
{
	if(this->is_empty()){
		cout << "nil graph" << endl;                      //空圖輸出nil
		return;
	}
	
	for(int i=0; i
void graph_mtx::depth_first(const T& vert)   //深度優先,認准一條路往死走,無路可走再回退
{
	int num = this->get_numvertices();
	bool *visited = new bool[num];

	memset(visited, 0, sizeof(bool)*num);          //首先全部賦值為假,遍歷過後為真,防止圖死循環
	depth_first(vert, visited); 
	cout << "end.";
	
	delete []visited;
}

template 
void graph_mtx::depth_first(const T& vert, bool *visited)
{
	cout << vert << "-->";

	int index = get_vertex_index(vert);
	visited[index] = true;

	int neighbor_index = get_firstneighbor(vert);
	while(neighbor_index != -1){
		if(!visited[neighbor_index])
			depth_first(get_vertex_symbol(neighbor_index), visited);   //遞歸
		
		neighbor_index = get_nextneighbor(vert,
								get_vertex_symbol(neighbor_index));
	}
}

template 
void graph_mtx::broad_first(const T& vert)
{
	int num = this->get_numvertices();
	bool *visited = new bool[num];
	int index = get_vertex_index(vert);
	assert(index != -1);
	
	memset(visited, 0, sizeof(bool)*num);
	
	queue que;                    //通過隊列,將元素以次入隊
	que.push(index);

	cout << vert << "-->";
	visited[index] = true;

	while(!que.empty()){
		int index_tmp = que.front();
		que.pop();

		int neighbor_index = get_firstneighbor(get_vertex_symbol(index_tmp));
		while(neighbor_index != -1){
			if(!visited[neighbor_index]){
				cout << get_vertex_symbol(neighbor_index) << "-->";
				visited[neighbor_index] = true;                  //遍歷過後為真,防止圖死循環
				que.push(neighbor_index);
			}
			neighbor_index = get_nextneighbor(get_vertex_symbol(index_tmp),
											  get_vertex_symbol(neighbor_index));
		}
	}
	cout << "end.";
	
	delete []visited;
}

//////////////////////////////////////////////////////////////////
//min_spactree_kruskal
template 
struct _mst_edge{                  //最小生成樹邊的結構體,為一組邊,cost為花費
	int begin;
	int end;
	E cost;
};

template 
int compare(const void* vp1, const void* vp2)  
{
	return (*(_mst_edge *)vp1).cost - (*(_mst_edge *)vp2).cost;
}

bool _is_same(int *father, int begin, int end)            //判斷是否在同一張子圖中
{
	while(father[begin] != begin)
		begin = father[begin];
	while(father[end] != end)
		end = father[end];        
	
	return begin == end;                       //以最後一個元素是否存在父子關系判斷
}

void mark_same(int *father, int begin, int end)
{
	while(father[begin] != begin)
		begin = father[begin];
	while(father[end] != end)
		end = father[end];
	
	father[end] = begin;                    //讓最後一個元素連接起來,使它們成為同一子圖的元素
}

template 
void graph_mtx::min_spantree_kruskal()
{
	int num = this->get_numvertices();
	_mst_edge *mst_edge = new _mst_edge[num*(num-1)/2];

	int k = 0;
	for(int i=0; i), compare);   //調用快速排序函數

	int *father = new int[num];          //初始化使所有元素的父指向自己
	for(int i=0; i
void graph_mtx::min_spantree_prim(const T& vert)
{
	int num = this->get_numvertices();
	int *lowcost = new int[num];   //最小花費數組
	int *mst = new int[num];       //起始位置數組  為一組邊,起始為mst[i]

	int index = get_vertex_index(vert);
	assert(index != -1);

	for(int i=0; i

三:測試部分

測試用圖: \ 測試代碼:
#include "graph.h"
#include "graph_mtx.h"

#define VERTEX_SIZE 4

int main()
{
	graph_mtx gm;
	
	gm.insert_vertex('A');
	gm.insert_vertex('B');
	gm.insert_vertex('C');
	gm.insert_vertex('D');
	gm.insert_vertex('E');
	gm.insert_vertex('F');
	
	gm.insert_edge('A', 'B', 6);
	gm.insert_edge('A', 'C', 1);
	gm.insert_edge('A', 'D', 5);
	gm.insert_edge('B', 'C', 5);
	gm.insert_edge('B', 'E', 3);
	gm.insert_edge('C', 'D', 5);
	gm.insert_edge('C', 'F', 4);
	gm.insert_edge('D', 'F', 2);
	gm.insert_edge('E', 'F', 6);
	gm.insert_edge('C', 'E', 6);
	gm.print_graph();

	cout << "depth_first traverse:" << endl;
	gm.depth_first('A');
	cout << endl;

	cout << "broad_first traverse:" << endl;
	gm.broad_first('A');
	cout << endl;
	
	cout << "min_spantree_kruskal :" << endl;
	gm.min_spantree_kruskal();
	cout << "min_spantree_prim :" << endl;
	gm.min_spantree_prim('A');
	
	return 0;
}
測試結果: \  
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