4.4.3邻接表的广度优先遍历

#include <bits/stdc++.h>
#include "Graph.cpp"

using namespace std;

void BFS(ALGraph *G, int v) { // 邻接表的BFS算法
  ArcNode *p;
  int w;
  int visited[MAXV];
  queue<int> qu; // 定义存放访问过的顶点的标志数组
  memset(visited, 0, sizeof(visited)); // 初始化访问标志数组
  cout << v << " ";
  visited[v] = 1;
  qu.push(v); // 访问过的顶点进队
  while(!qu.empty()) {
    w = qu.front();
    qu.pop(); // 出队顶点w
    p = G->adjlist[w].firstarc; // 找到顶点w的第一个邻接点
    while(p != NULL) {
      if(visited[p->adjvex] == 0) {
        cout << p->adjvex << " ";
        visited[p->adjvex] = 1;
        qu.push(p->adjvex);
      }
      p = p->nextarc; // 找到顶点w的下一个邻接点
    }
  }
  cout << endl;
}

int main() {
  ALGraph *G;
  int A[][MAXV]= {
    {0,1,0,0,1},
    {0,0,1,1,1},
    {0,0,0,0,0},
    {0,0,1,0,1},
    {0,0,0,0,0}
  };
  int n=5,e=7;
  CreateAdj(G, A, n, e); //创建图的邻接表存储结构G
  cout << "图的邻接表如下：" << endl;
  DispAdj(G);
  cout << "图的邻接表的广度优先遍历如下：" << endl; 
  BFS(G, 0); 
  return 0;
}

#include <bits/stdc++.h>
#define MAXV 50 // 最大顶点个数
#define MAXL 20
#define INF 0x3f3f3f3f  //表示∞ 

using namespace std;

typedef struct ANode {
  int adjvex; // 该边的终点编号
  int weight; // 改变的权值
  struct ANode *nextarc; //指向下一条边的指针
} ArcNode; // 边结点的类型

typedef struct Vnode {
  char data[MAXL]; // 顶点信息
  ArcNode *firstarc; // 指向第一条边
} VNode; // 邻接表的表头的结点类型

typedef VNode AdjList[MAXV]; // AdjList是邻接表类型

typedef struct {
  AdjList adjlist; // 邻接表
  int n, e; // 图中的顶点数和边数
} ALGraph; // 图

void CreateAdj(ALGraph *&G, int A[][MAXV], int n, int e) { //建立图的邻接表
  ArcNode *p;
  G = (ALGraph *) malloc (sizeof(ALGraph));
  G->n = n;
  G->e = e;
  for(int k = 0; k < n; k++)
    G->adjlist[k].firstarc = NULL;
  for(int i = 0; i < n; i++)
    for(int j = 0; j < n; j++)
      if(A[i][j] != 0 && A[i][j] != INF) {
        p = (ArcNode *) malloc (sizeof(ArcNode));
        p->adjvex = j;
        p->weight = A[i][j];
        p->nextarc = G->adjlist[i].firstarc;
        G->adjlist[i].firstarc = p;
      }
}

void DispAdj(ALGraph *G) {
  ArcNode *p;
  for(int i = 0; i < G->n; i++) {
    cout << i;
    p = G->adjlist[i].firstarc;
    while(p != NULL) {
      cout << "->" << "结点编号：" << p->adjvex << " 边的权值：" << p->weight;
      p = p->nextarc;
    }
    cout << "^" << endl;
  }
}

void DestroyAdj(ALGraph *&G) { // 销毁图的邻接表
  ArcNode * pre ,*p;
  for(int i = 0; i < G->n; i++) {
    pre = G->adjlist[i].firstarc;
    while(pre != NULL) {
      p = pre->nextarc;
      free(pre);
      pre = p;
    }
  }
  free(G);
}