dfs-bfs

/图的遍历是指按某条搜索路径访问图中每个结点，使得每个结点均被访问一次，而且仅被访问一次。图的遍历有深度遍历算法和广度遍历算法 #include <malloc.h>  
#include <iostream>  
using namespace std;  
  
#define INFINITY 32767  
#define MAX_VEX 50 //最大顶点个数  
#define QUEUE_SIZE (MAX_VEX+1) //队列长度

 
#define OK 1  
#define FALSE 0  
#define TRUE 1  
#define ERROR -1  
   
bool *visited;  //动态分配访问标志数组  
   
//图的邻接矩阵存储结构  
typedef struct {  
    char *vexs;  //动态分配空间存储顶点向量  
    int arcs[MAX_VEX][MAX_VEX];  //邻接矩阵  
    int vexnum, arcnum;  //图的当前定点数和弧数   
}Graph;  

//队列类
class Queue{
public:
  void InitQueue(){
    base=(int *)malloc(QUEUE_SIZE*sizeof(int));
    front=rear=0;
  }
  void EnQueue(int e){
    base[rear]=e;
    rear=(rear+1)%QUEUE_SIZE;
  }
  void DeQueue(int &e){
    e=base[front];
    front=(front+1)%QUEUE_SIZE;
  }
  public:
	int *base;
	int front;
	int rear;  
};
  
  
//图G中查找顶点c的位置  
int LocateVex(Graph G, char c) {  
    for(int i = 0; i < G.vexnum; ++i) {  
        if(G.vexs[i] ==  c) return i;  
    }  
    return ERROR;  
}  
    
//创建无向网  
void CreateUDN(Graph &G){  
    //采用数组（邻接矩阵）表示法，构造无向网G  
    cout << "请输入定点数和弧数：";  
    cin >> G.vexnum >> G.arcnum;  
    cout << "请输入" << G.vexnum << "个顶点" << endl;  
    G.vexs = (char *) malloc((G.vexnum+1) * sizeof(char));  //需要开辟多一个空间存储'\0'  
    //构造顶点向量  
    for(int i = 0; i < G.vexnum; i++) {  
        cout << "请输入第" << i+1 << "个顶点：";  
        cin >> G.vexs[i];  
    }  
    G.vexs[G.vexnum] = '\0';  
      
    //初始化邻接矩阵  
    for(i = 0; i < G.vexnum; ++i)   
        for( int j = 0; j < G.vexnum; j++)   
            G.arcs[i][j] = INFINITY;     
      
    cout << "请输入" << G.arcnum << "条弧" << endl;  
    char a, b;  
    int s1, s2;  
    for(i = 0; i < G.arcnum; ++i) {  
        cout << "请输入第" << i+1 << "条弧：";  
        cin >> a >> b ;  //输入依附于弧的权值  
        s1 = LocateVex(G,a);  //找到a和b在顶点向量中的位置  
        s2 = LocateVex(G,b);    
        G.arcs[s1][s2] = G.arcs[s2][s1] = 1;  //权值默认为1  
    }  
}  
  
//图G中顶点k的第一个邻接顶点  
int FirstVex(Graph G,int k){  
    for(int i = 0; i < G.vexnum; ++i)   
        if (G.arcs[k][i] != INFINITY) return i;  
    return ERROR;  
}  
  
//返回i（相对于j）的下一个邻接顶点  
int NextVex(Graph G,int i,int j){  
    for(int k = j+1; k < G.vexnum; ++k)   
        if(G.arcs[i][k] != INFINITY) return k;  
    return ERROR;  
}  
  
void DFS(Graph G, int v) {  
    //从第v个顶点出发递归地深度优先遍历图G  
    visited[v] = TRUE;  
    cout << G.vexs[v] << "  ";  
    for(int w = FirstVex(G,v); w >= 0; w = NextVex(G,v,w))  
        if(!visited[w]) DFS(G,w);  
}  
  
//深度优先遍历  
void DFSTraverse(Graph G, int i) {  
    for(int j = 0; j < G.vexnum; ++j) {  //初始化所有的顶点状态为未被访问  
        visited[j] = FALSE;  
    }  
    //遍历结点  
    for(; i < G.vexnum; ++i)   
        if(!visited[i]) DFS(G,i);  
}  
  
//广度优先遍历
void BFS(Graph G){
  int k;
  Queue Q; //辅助队列Q
  Q.InitQueue();
  for(int i=0;i<G.vexnum;i++)
    if(!visited[i]){ //i尚未访问
      visited[i]=true;
      printf("%c ",G.vexs[i]);
      Q.EnQueue(i); //i入列
      while(Q.front!=Q.rear){//队非空，出队
        Q.DeQueue(k); //队头元素出列并置为k
        for(int w=FirstVex(G,k);w>=0;w=NextVex(G,k,w))
          if(!visited[w]){ //w为k的尚未访问的邻接顶点
            visited[w]=true;
            printf("%c ",G.vexs[w]);
            Q.EnQueue(w);
          }
      }
    }
}


//主函数  
void main(){  
    Graph G;  
    CreateUDN(G);  
    visited = (bool *) malloc(G.vexnum * sizeof(bool));  
    cout << endl << "深度优先遍历：";  
    DFSTraverse(G,0);  
    cout << endl << "广度BFS优先遍历：";  
    BFS(G);  


    cout << endl;  
} 

  

 

输入顶点数和弧数:8 9
输入8个顶点.
输入顶点0:a
输入顶点1:b
输入顶点2:c
输入顶点3:d
输入顶点4:e
输入顶点5:f
输入顶点6:g
输入顶点7:h

输入9条弧.
输入弧0:a b 1
输入弧1:b d 1
输入弧2:b e 1
输入弧3:d h 1
输入弧4:e h 1
输入弧5:a c 1
输入弧6:c f 1
输入弧7:c g 1
输入弧8:f g 1
深度优先遍历: a b d h e c f g
广度优先遍历: a b c d e f g h
程序结束.