【图】BFS和DFS

一、BFS

#include<iostream>
#include<queue>
using namespace std;

const int max_num = 100;

class BFS{
public:
	typedef int VertexType;
	typedef int EdgeType;
	BFS();
	void create_graph();
	void bfs_traverse();
private:
	EdgeType arc[max_num][max_num];
	bool visited[max_num];
	queue<EdgeType> que; //辅助队列
	int vertex_num;
	int edge_num;
};
BFS::BFS(){
	for (int i = 0; i < max_num; i++){
		for (int j = 0; j < max_num; j++){
			arc[i][j] = 0;
		}
	}
	memset(visited, false, sizeof(visited));
	while (!que.empty())
		que.pop();
}
void BFS::create_graph(){
	int i, j, k;
	cout << "请输入图的顶点数和边数：" << endl;
	cin >> vertex_num >> edge_num;
	for (i = 0; i < edge_num; i++){
		cout << "输入边（vj，vk）上的上标j，下标k" << endl;
		cin >> j >> k;
		arc[j][k] = arc[k][j] = 1;
	}
}
void BFS::bfs_traverse(){
	for (int i = 0; i < vertex_num; i++){
		if (!visited[i]){
			visited[i] = true;
			cout << i << " ";
			que.push(i);
			while (!que.empty()){
				int k = que.front();
				que.pop();
				for (int j = 0; j < vertex_num; j++){
					if (arc[k][j] == 1 && !visited[j]){
						visited[j] = true;
						cout << j << " ";
						que.push(j);
					}
				}
			}
		}
	}
}

int main(){
	BFS bfs;
	bfs.create_graph();
	bfs.bfs_traverse();

	return 0;
}

二、DFS

#include<iostream>
using namespace std;

const int max_num = 100;

class DFS{
public:
	typedef int VertexType;
	typedef int EdgeType;
	DFS();
	void create_graph();
	void dfs(int i);
	void dfs_traverse();
private:
	EdgeType arc[max_num][max_num];
	bool visited[max_num];
	int vertex_num;
	int edge_num;
};
DFS::DFS(){
	for (int i = 0; i < max_num; i++){
		for (int j = 0; j < max_num; j++){
			arc[i][j] = 0;
		}
	}
	memset(visited, false, sizeof(visited));
}
void DFS::create_graph(){
	int i, j, k;
	cout << "请输入图的顶点数和边数：" << endl;
	cin >> vertex_num >> edge_num;
	for (i = 0; i < edge_num; i++){
		cout << "输入边（vj，vk）上的上标j，下标k" << endl;
		cin >> j >> k;
		arc[j][k] = arc[k][j] = 1;
	}
}
void DFS::dfs(int i){
	visited[i] = true;
	cout << i << " ";
	for (int j = 0; j < vertex_num; j++){
		if (arc[i][j] == 1 && !visited[j])
			dfs(j); //对未访问的邻接顶点递归调用 
	}
}
void DFS::dfs_traverse(){
	for (int i = 0; i < vertex_num; i++){
		if (!visited[i])
			dfs(i);
	}
}

int main(){
	DFS dfs;
	dfs.create_graph();
	dfs.dfs_traverse();

	return 0;
}