无向图的邻接表遍历：深度优先搜索+广度优先搜索

#include <iostream>
#include <malloc.h>
#include <queue>

#define NumVertex 20

bool visited[NumVertex];
using namespace std;

typedef struct node{
    int adjvex;
    node *next;
}EgdeNode;

typedef struct{
    int vertex;
    EgdeNode *firstedge;
}VertexNode;
typedef struct{
    VertexNode vexlist[NumVertex];
    int n,e;
}AdjGraph;

void CreateGraph(AdjGraph *G){
    int i,head,tail;
    cout << "请输入顶点数和边数：" << endl;
    cin >> G->n >> G->e ;
    cout << "请输入顶点信息：" << endl;
    for( i=0 ; i < G->n ; i++ ){
        cin >> G->vexlist[i].vertex ;
        G->vexlist[i].firstedge = NULL ;
    }
    for( i=0 ; i < G->e ; i++ ){
        cout << "请输入边（i, j)的上标，下标:" << endl;
        cin >> tail >> head ;
        EgdeNode * p = (EgdeNode *)malloc(sizeof(node));
        p -> adjvex = head;
        p -> next = G->vexlist[tail].firstedge;
        G->vexlist[tail].firstedge = p;
        EgdeNode * q = (EgdeNode *)malloc(sizeof(node));
        q -> adjvex = tail;
        q -> next = G->vexlist[head].firstedge;
        G->vexlist[head].firstedge = q;
    }
}

/*void ShowView(AdjGraph *G){
    int i;
    for( i=0 ; i< G->n ; i++){
        EgdeNode * p = (EgdeNode *)malloc(sizeof(node));
        cout << G->vexlist[i].vertex <<" ";
        p = G->vexlist[i].firstedge;
        while(p){
            cout << p->adjvex <<" ";
        }
        cout<<endl;
    }
}*/
void DFS(AdjGraph *G , int i){
    EgdeNode * p = (EgdeNode *)malloc(sizeof(node));
    cout << G->vexlist[i].vertex <<" ";
    visited[i] = true;
    p = G->vexlist[i].firstedge;
    while(p){
        if( !visited[p->adjvex] )  DFS(G,p->adjvex);
        p = p->next;
    }
}

void DFSTraverse(AdjGraph *G){
    int i;
    for( i = 0 ; i < G->n ; i++ ){
        visited[i] = false ;
    }
    for ( i= 0 ; i < G->n ; i++ ){
        if(!visited[i])  DFS(G,i);
    }
}

void BFS(AdjGraph *G , int i){
    queue <int> Q;
    EgdeNode * p = (EgdeNode *)malloc(sizeof(node));
    cout << G->vexlist[i].vertex <<" ";
    visited[i] = true;
    Q.push(i);
    while( !Q.empty() ){
        i = Q.front();
        Q.pop();
        p = G->vexlist[i].firstedge;
        while(p){
            if( !visited[p->adjvex] ){
                cout << G->vexlist[p->adjvex].vertex << " ";
                visited[p->adjvex] = true ;
                Q.push(p->adjvex);
            }
            p = p->next;
        }
    }
}

void BFSTraverse(AdjGraph *G){
    int i;
    for( i = 0 ; i < G->n ; i++ ){
        visited[i] = false ;
    }
    for ( i= 0 ; i < G->n ; i++ ){
        if(!visited[i]) BFS(G,i);
    }
}

int main()
{
    AdjGraph G;
    CreateGraph(&G);
//    ShowView(&G);
    cout<<"深度优先遍历:";
    DFSTraverse(&G);
    cout<<endl;
    cout<<"广度优先遍历:";
    BFSTraverse(&G);
    return 0;
}