使用STL进行竞争性编程实现图形实现|设置1(DFS的未加权和未定向)

我们在Graph及其表示中介绍了Graph基础。在这篇文章中，使用了不同的基于STL的表示形式，这有助于使用向量快速实现图形。该实现用于图形的邻接表表示。
以下是具有5个顶点的示例无向图和无权图。

下面是该图的邻接列表表示。

我们在STL中使用向量来使用邻接表表示实现图。

• vector：序列容器。在这里，我们使用它来存储所有顶点的邻接列表。我们使用顶点数作为该向量的索引。

想法是将图表示为向量数组，以使每个向量都代表一个顶点的邻接表。下面是用于DFS遍历的完整的基于STL的C++程序。

C++

// A simple representation of graph using STL,
// for the purpose of competitive programming
#include
using namespace std;
 
// A utility function to add an edge in an
// undirected graph.
void addEdge(vector adj[], int u, int v)
{
    adj[u].push_back(v);
    adj[v].push_back(u);
}
 
// A utility function to do DFS of graph
// recursively from a given vertex u.
void DFSUtil(int u, vector adj[],
                    vector &visited)
{
    visited[u] = true;
    cout << u << " ";
    for (int i=0; i adj[], int V)
{
    vector visited(V, false);
    for (int u=0; u *adj = new vector[V];
    vector adj[V];
 
    // Vertex numbers should be from 0 to 4.
    addEdge(adj, 0, 1);
    addEdge(adj, 0, 4);
    addEdge(adj, 1, 2);
    addEdge(adj, 1, 3);
    addEdge(adj, 1, 4);
    addEdge(adj, 2, 3);
    addEdge(adj, 3, 4);
    DFS(adj, V);
    return 0;
}

Python3

# A simple representation of graph using STL,
# for the purpose of competitive programming
 
# A utility function to add an edge in an
# undirected graph.
def addEdge(adj, u, v):
    adj[u].append(v)
    adj[v].append(u)
    return adj
 
# A utility function to do DFS of graph
# recursively from a given vertex u.
def DFSUtil(u, adj, visited):
    visited[u] = True
    print(u, end = " ")
    for i in range(len(adj[u])):
        if (visited[adj[u][i]] == False):
            DFSUtil(adj[u][i], adj, visited)
 
# This function does DFSUtil() for all
# unvisited vertices.
def DFS(adj, V):
    visited = [False]*(V+1)
 
    for u in range(V):
        if (visited[u] == False):
            DFSUtil(u, adj, visited)
 
# Driver code
if __name__ == '__main__':
    V = 5
 
    # The below line may not work on all
    # compilers.  If it does not work on
    # your compiler, please replace it with
    # following
    # vector *adj = new vector[V]
    adj = [[] for i in range(V)]
 
    # Vertex numbers should be from 0 to 4.
    adj = addEdge(adj, 0, 1)
    adj = addEdge(adj, 0, 4)
    adj = addEdge(adj, 1, 2)
    adj = addEdge(adj, 1, 3)
    adj = addEdge(adj, 1, 4)
    adj = addEdge(adj, 2, 3)
    adj = addEdge(adj, 3, 4)
    DFS(adj, V)
 
# This code is contributed by mohit kumar 29.

Javascript

// A simple representation of graph using STL,
// for the purpose of competitive programming
     
     
    // A utility function to add an edge in an
// undirected graph.
    function addEdge(adj,u,v)
    {
        adj[u].push(v);
        adj[v].push(u);
    }
     
    // A utility function to do DFS of graph
// recursively from a given vertex u.
    function DFSUtil(u,adj,visited)
    {
        visited[u] = true;
        document.write(u+" ");
    for (let i=0; i<adj[u].length; i++)
        if (visited[adj[u][i]] == false)
            DFSUtil(adj[u][i], adj, visited);
    }
     
    // This function does DFSUtil() for all
// unvisited vertices.
    function DFS(adj,V)
    {
        let visited=new Array(V);
        for(let i=0;i<V;i++)
        {
            visited[i]=false;
        }
    for (let u=0; u<V; u++)
        if (visited[u] == false)
            DFSUtil(u, adj, visited);
    }
     
    // Driver code
    let V = 5;
     
    // The below line may not work on all
    // compilers.  If it does not work on
    // your compiler, please replace it with
    // following
    // vector<int> *adj = new vector<int>[V];
    let adj=new Array(V);
    for(let i=0;i<V;i++)
    {
        adj[i]=[];
    }
     
    // Vertex numbers should be from 0 to 4.
    addEdge(adj, 0, 1);
    addEdge(adj, 0, 4);
    addEdge(adj, 1, 2);
    addEdge(adj, 1, 3);
    addEdge(adj, 1, 4);
    addEdge(adj, 2, 3);
    addEdge(adj, 3, 4);
    DFS(adj, V);
     
     
     
    // This code is contributed by unknown2108

输出 ：

0 1 2 3 4

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