图的深度优先遍历c++实现

Posted 2022-10-16 wlw-x

图的深度优先遍历c++实现

• 深度优先搜索

---

邻接矩阵的创建

    int i, j, m, a, b;
    cin >> n >> m;
    //初始化二维矩阵
    for (i = 1; i <= n; i++)
        for (j = 1; j <= n; j++)
            if (i == j)e[i][j] = 0;
            else e[i][j] = 0x3f;

    //读入顶点之间的边
    for (i = 1; i <= m; i++)
    
        cin >> a >> b;
        e[a][b] = 1;
        e[b][a] = 1; //无向图需要将其对应的点的左边也赋值为1
    

---

深度优先搜索算法实现

void dfs(int cur)

    int i;
    cout << cur << " ";
    sum++;//每访问一个节点sum就++
    if (sum == n)return;//所有的顶点已经访问过直接退出
    for (int i = 1; i <= n; i++)
    
        //判断当前顶点cur到顶点i是否有边,并判断顶点i是否已经访问过
        if (e[cur][i] == 1 && book[i] == 0)
        
            book[i] = 1;
            dfs(i);
        
    
    return;

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整体代码

#include <iostream>
#include <cstdio>
using namespace std;
int book[101], sum, n, e[101][101];

void dfs(int cur)

    int i;
    cout << cur << " ";
    sum++;//没访问一个节点sum就++
    if (sum == n)return;//所有的顶点已经访问过直接退出
    for (int i = 1; i <= n; i++)
    
        //判断当前顶点cur到顶点i是否有边,并判断顶点i是否已经访问过
        if (e[cur][i] == 1 && book[i] == 0)
        
            book[i] = 1;
            dfs(i);
        
    
    return;

int main()

    int i, j, m, a, b;
    cin >> n >> m;
    //初始化二维矩阵
    for (i = 1; i <= n; i++)
        for (j = 1; j <= n; j++)
            if (i == j)e[i][j] = 0;
            else e[i][j] = 0x3f;

    //读入顶点之间的边
    for (i = 1; i <= m; i++)
    
        cin >> a >> b;
        e[a][b] = 1;
        e[b][a] = 1; //无向图需要将其对应的点的左边也赋值为1
    

    //从顶点1出发
    book[1] = 1;//标记一号顶点已经被访问
    dfs(1);//从1号顶点开始遍历
    system("pause");
    return 0;