Question

$ make -f makefile.txt
g++ -Wall -W -Werror -pedantic -g -c MinPriority.cpp
MinPriority.cpp: In member function `void MinPriority::createArray()':
MinPriority.cpp:50: error: expected primary-expression before '&' token
MinPriority.cpp:50: error: expected primary-expression before ',' token
MinPriority.cpp:50: error: expected primary-expression before "targetVertex"
makefile.txt:7: recipe for target `MinPriority.o' failed
make: *** [MinPriority.o] Error 1

基本上我正在尝试访问Graph.h的函数（位于私有:)，其目的是通过引用传递给定索引处的链表的向量。基本上，它查看链接列表的向量，转到向量的某个索引，并将其链接列表转换为向量，并通过引用将其传递给另一个文件中的函数。这是发生错误的地方。

void MinPriority::createArray()
{
    Graph::get_adjLine(vector<Edge>&, string targetVertex); //MinPriority.ccp.50: error
}

这是函数get_adjLine()本身：

void Graph::get_adjLine(vector<Edge>& v, string targetVertex) //passes back a node and its adjacencies in the form of a vector
{
    //vector<Edge> v;
    int index;
    for(unsigned int i = 0; i != adjList.size(); i++) //find the targetVertex's index
    {
        if(adjList[i].front().m_vertex == targetVertex)
        {
            index = i;
            continue;
        }
    }
    copy(adjList[index].begin(), adjList[index].end(), v.begin());
}

我目前正在尝试找到将vector< list<Edge> > adjList;的私有结构传递到MinPriority::createArray()的任何可行方法。任何方式对我来说都是最好的，但我花了最后几个小时试图想出办法，但我无法弄明白。以下是类声明：Graph.h

#ifndef GRAPH_H_INCLUDED
#define GRAPH_H_INCLUDED
//class MinPriority;
#include <iostream>
#include <string>
#include <vector>
#include <list>
#include <locale>
using namespace std;
//class MinPriority;
class Graph
{
public:
    Graph();
    ~Graph();
    void set_Edge(string targetVertex, string vertex, int weight);
    void set_array(string vertex);
    void ABC_array();
    void print_Test();
    friend class MinPriority; //allow MinPriority to access private functions/variables
private:
    class Edge
    {
    public:
        Edge(string vertex, int weight)
        {m_vertex = vertex; m_weight = weight;}
        ~Edge(){}
        string m_vertex;
        int m_weight;
    };
    void get_adjLine(vector<Edge>&, string targetVertex);
    vector< list<Edge> > adjList;

};


#endif // GRAPH_H_INCLUDED

和MinPriority.h

#ifndef MINPRIORITY_H_INCLUDED
#define MINPRIORITY_H_INCLUDED
#include <iostream>
#include <string>
#include <vector>
#include <list>
using namespace std;
class Graph; //letting MinPriority know about Graph
class Edge; //letting MinPriority know about Graph::Edge
class MinPriority
{
    //Min heap property: A[PARENT(i)] <= A[i];
public:
    MinPriority();
    ~MinPriority();
    void createArray();
    void MIN_HEAPIFY(int);
    void BUILD_MIN_HEAP(int);
    string HEAP_MINIMUM();
    void INSERT(int);
    int HEAP_SIZE();
    int PARENT(int);
    int LEFT(int);
    int RIGHT(int);
private:
    class priority
    {
        priority(string preVertex, string vertex, int weight)
        {m_preVertex = preVertex; m_vertex = vertex; m_weight = weight;}
        ~priority(){}
        string m_preVertex;
        string m_vertex;
        int m_weight;
    };
    vector<priority> heapArray;
    vector<priority> priorityQueue;
};


#endif // MINPRIORITY_H_INCLUDED

Answer 1

首先，Graph::get_adjLine不是静态成员函数，所以你不能这样调用它：

Graph::get_adjLine(....)

您需要在实例上调用它：

Graph g = ....;
g.get_adjLine(.....);

其次，你需要传递一些参数。您似乎在函数调用中使用函数声明语法：

Graph :: get_adjLine（vector＆amp; adjList，string targetVertex）;

应该是

g.get_adjLine(someEdgeVector, someString);

Answer 2

您是否尝试这样做：

void MinPriority::createArray()
    {
        Graph::get_adjLine(vector<Edge>& adjList, string targetVertex);
    }

实际上，由于adjList是Graph类的成员，因此您无需将其作为成员函数中的参数传递。你可以直接使用它。

如何通过位于单独类中的引用传递向量

2 个答案: