c++ - 从堆栈弹出值

Question

#include <iostream>
#include <stack>

using namespace std;

int main()
{
     stack<int> S;

     int n, x;

     cout << "Enter number of values that     will be pushed into the stack: ";
     cin >> n;

     for(int i = 1; i < n; i++){
        cout << "Value " << i << ": ";
        cin >> x;
        S.push(x);
     }

     cout << endl;
     cout << "Output: " << endl;

     while(!S.empty()){
          cout << "| ";
          S.pop();
          cout << " |" << endl;
     }
}

大家好。这是我的代码。如果我在堆栈中输入这些值:3、7、2、9、1 并希望像这样显示:

| 1 |
| 9 |
| 2 |
| 7 |
| 3 |

但我最终得到:

|    |
|    |
|    |
|    |
|    |

请帮忙。

Answer 1

使用 S.top() 获取最顶层元素，使用 S.pop() 将其从顶部移除。

#include <iostream>
#include <stack>

using namespace std;

int main()
{
     stack<int> S;

     int n, x;

     cout << "Enter number of values that will be pushed into the stack: ";
     cin >> n;

     for(int i = 1; i < n; i++) {
        cout << "Value " << i << ": ";
        cin >> x;
        S.push(x);
     }

     cout << endl;
     cout << "Output: " << endl;

     while(!S.empty()) {
          /************* Change here ****************/
          cout << "| " << S.top() << " |" << endl;
          S.pop();
     }
}