如何查找升壓圖中是否存在頂點？

Question

我有一個提升圖（捆綁屬性）。我想查找圖中是否已經存在具有特定值的頂點。有人可以幫我弄這個嗎？在這裏，我提出我的現有代碼MWE：

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#include <iostream> 
#include <string> 
#include <vector> 
#include <boost/graph/adjacency_list.hpp> 

struct mytuple 
{ 
    int e1; 
    int e2; 
    int s; 

    bool operator==(const mytuple& a) const 
    { 
     return ((e1 == a.e1) && (e2 == a.e2) && (s == a.s)); 
    } 
}; 

struct MyVertex { 
    std::string comments; 
    int field1; 
    mytuple value; 
    MyVertex(std::string comments = std::string()) : comments(comments) {} 
}; 

struct MyEdge { 
    std::string label; 
    MyEdge(std::string label = std::string()) : label(label) {} 
}; 

// Define the graph with the vertex as a mytuple and the vertices container as a vector 
using MyTree = boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, MyVertex, MyEdge>; 
using Vertex = boost::graph_traits<MyTree>::vertex_descriptor; // Define Vertex 
using VertexItr = boost::graph_traits<MyTree>::vertex_iterator; // Define Vertex iterator 
using Edge = std::pair<boost::graph_traits<MyTree>::edge_descriptor, bool>; // Define Edge 
using EdgeItr = boost::graph_traits<MyTree>::edge_iterator; // Define Edge Iterator 

int main() 
{ 
    MyTree mytree; 

    Vertex v1 = boost::add_vertex(mytree); 
    mytree[v1].value = {1, 1, 1}; 

    Vertex v2 = boost::add_vertex(mytree); 
    mytree[v2].value = {2, 2, 2}; 

    Vertex v3 = boost::add_vertex(mytree); 
    mytree[v3].value = {3, 3, 3}; 

    // Perhaps add some edges 

    std::cout << "I want to find if my graph has a vertex containing the value {1, 1, 1}"; 
    // mytree.findvertex(with value {1, 1, 1}) 
} 

Answer 1

#include <iostream> 
#include <string> 
#include <vector> 
#include <boost/graph/adjacency_list.hpp> 


struct mytuple 
{ 
    int e1; 
    int e2; 
    int s; 

    bool operator==(const mytuple& a) const 
    { 
     return ((e1 == a.e1) && (e2 == a.e2) && (s == a.s)); 
    } 
}; 

struct MyVertex { 
    std::string comments; 
    int field1; 
    mytuple value; 
    MyVertex(std::string comments = std::string()) : comments(comments) {} 
}; 

struct MyEdge { 
    std::string label; 
    MyEdge(std::string label = std::string()) : label(label) {} 
}; 

// Define the graph with the vertex as a mytuple and the vertices container as a vector 
using MyTree = boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, MyVertex, MyEdge>; 
using Vertex = boost::graph_traits<MyTree>::vertex_descriptor; // Define Vertex 
using VertexItr = boost::graph_traits<MyTree>::vertex_iterator; // Define Vertex iterator 
using Edge = std::pair<boost::graph_traits<MyTree>::edge_descriptor, bool>; // Define Edge 
using EdgeItr = boost::graph_traits<MyTree>::edge_iterator; // Define Edge Iterator 

VertexItr findvertex(const MyTree& g, const mytuple& value){ 
    VertexItr vi, vi_end; 
    for (boost::tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi) { 
     if(g[*vi].value == value) return vi; 
    } 
    return vi_end; 
} 

int main() 
{ 
    MyTree mytree; 

    Vertex v1 = boost::add_vertex(mytree); 
    mytree[v1].value = {1, 1, 1}; 
    mytree[v1].comments = "I am the one you seek"; 

    Vertex v2 = boost::add_vertex(mytree); 
    mytree[v2].value = {2, 2, 2}; 

    Vertex v3 = boost::add_vertex(mytree); 
    mytree[v3].value = {3, 3, 3}; 

    // Perhaps add some edges 

    std::cout << "I want to find if my graph has a vertex containing the value {1, 1, 1}\n"; 
    mytuple tuple = { 1,1,1}; 
    const auto iter = findvertex(mytree, tuple); 
    const auto theEnd = boost::vertices(mytree).second; 
    if(iter != theEnd){ 
    std::cout << "'ere I be: " << mytree[*iter].comments << '\n'; 
    } 
    else{ 
     std::cout << "failed to find tuple\n"; 
    } 
} 

與g++ graph.cpp -std=c++11 -o graph.o -l boost_graph 編譯產生的輸出中

I want to find if my graph has a vertex containing the value {1, 1, 1} 
'ere I be: I am the one you seek