Question

尝试实现邻接矩阵图并练习OOP。我一直坚持执行inserNode（string）方法。

我的麻烦在于访问私有数据字段。我完全想念什么？

某些错误：

Graph.cpp：30：26：错误：未知类型名称'node' graph [id] =新节点； ^

Graph.cpp：35：10：错误：使用未声明的标识符'numnodes' numnodes ++;

Graph.cpp：34：19：错误：预期为';'声明结束时 graph [id]-> nodename = name;

Graph.cpp：34：15：错误：分解声明'[id]'需要初始化程序

graph.h

#include <iostream>
using namespace std;

class Graph {

    public:
        Graph();
        int insertNode(string name);

    private:
        static const int vertices = 20;
        int nodeCount;

        struct node {
            int nodeid; // node position in graph[]
            string nodename; // username
        };

        // pointers to the graph nodes 
        node *graph[vertices];

        // adjacency matrix for graph. True if edge is going from node i to j.
        bool edges[vertices][vertices];
};

#endif

graph.cpp

#include "Graph.h"

Graph::Graph() {
    for (int i = 0; i < vertices; i++) {
        graph[i] = 0;
        for (int j = 0; j < vertices; j++ )
            edges[i][j] = 0;
    }
}

      /* create node and insert pointer in first  available graph position. Returns id value, -1 if unsuccessful. */
int insertNode(string name) {
    int id = 0;
    while (id < vertices) {
        if (graph[id] == NULL) {
            graph[id] = new node;
                if (!graph[id]) 
                    return -1;
                 graph[id]->nodeid = id;
                 graph[id]->nodename = name;
                 numnodes++;
                 return id;
        }
        id++;
   }
   return -1;
}

Answer 1

您定义的insertNode与您在Graph中声明的方式不同。您刚刚制作了一个名为insertNode的免费函数，该函数不是Graph的成员，因此无法访问Graph。您需要这样定义它：

int Graph::insertNode(string name)
{
}

在类C ++中访问私有结构

1 个答案: