c++ - 如何在 C++ 中创建类对象的 vector ？

Question

我正在尝试使用 C++ 中的 vector 创建一个简单的堆栈。

代码如下:

#include <vector>

class Site
{
    public:
        int i; // site position i (x-axis)
        int s; // site state
        vector<Site> neighbors;
        Site(void);
        Site(int ii, int ss);
        void AddNeighbor(Site &site);
};
Site::Site()
{
    i = -1;
    s = -1;
    vector<Site> neighbors;
}
Site::Site(int ii, int ss) 
{
    i = ii;
    s = ss;
}
void Site::AddNeighbor(Site &site)
{
    neighbors.push_back(site);
}

void testStack()
{
    int tot = 600;
    vector<Site> myStack();
    int i = 0;
    while (i < tot)
    {
        Site site(i, 1);
        myStack.push_back(site);
        i++;
    }

    i = 0;
    while (i < tot)
    {
        Site *site = myStack.back();
        myStack.pop_back();
        cout << site->i << site->s << endl;
        i++;
    }
}

编译器错误:

ising_wolff.cpp: In function ‘void testStack()’: ising_wolff.cpp:373:17: error: request for member ‘push_back’ in ‘myStack’, which is of non-class type ‘std::vector()’ myStack.push_back(site); ^ ising_wolff.cpp:380:30: error: request for member ‘back’ in ‘myStack’, which is of non-class type ‘std::vector()’ Site *site = myStack.back(); ^ ising_wolff.cpp:381:17: error: request for member ‘pop_back’ in ‘myStack’, which is of non-class type ‘std::vector()’ myStack.pop_back();

这些错误是什么意思？

以下是我浏览过的一些网站:

1) Creating objects while adding them into vectors

2) push_back causing errors in C

3) how to create vectors of class object

Answer 1

如何在 C++ 中创建类对象的 vector ？

从更简单的事情开始，这样您就可以掌握它。

首先，创建一个原始整数 vector :

#include <vector>
#include <iostream>
using namespace std;
int main(){
  vector<int> sites(5);
  sites.push_back(5);
  for(int x = 0; x < sites.size(); x++){
    cout << sites[x];
  }
  cout << endl;
  return 0;
}

编译它:

g++ -o test test.cpp

运行它:

./test
000005

以与上述类似的方式创建类对象的 vector :

#include <iostream>
#include <vector>
using namespace std;

class Site {
public:
    int i;
};

int main() {
    vector<Site> listofsites;
    Site *s1 = new Site;
    s1->i = 7;
    Site *s2 = new Site;
    s2->i = 9;
    listofsites.push_back(*s1);
    listofsites.push_back(*s2);
    vector<Site>::iterator it;
    for (it = listofsites.begin(); it != listofsites.end(); ++it) {
        cout << it->i;
    }
    return 0;
}

应该打印:

79