C ++中的結構選擇類型

Question

我的任務是創建一個選擇排序算法來存儲數據。 所以我使用struct來存儲數據，並且已經實現了選擇排序，但是我對結果確實感到困惑。 我感謝您的幫助。

#include <iostream>
#include <vector>
#include <cstdlib>
#include <vector>
#include <string>

using namespace std;

struct employee
{
    string name;
    int salary;
};

void swap(int& x, int& y)
{
    int temp = x;
    x = y;
    y = temp;
}


int min_position(vector<employee>& a, int from, int to)
{
    int min_pos = from;
    int i;
    for (i = from + 1; i <= to; i++)
        if (a[i].salary < a[min_pos].salary)
            min_pos = i;
    return min_pos;
}

void selection_sort(vector<employee>& a)
{
    int next; // the next position to be set to the minimum

    for (next = 0; next < a.size() - 1; next++)
    { // find the position of the minimum
        int min_pos = min_position(a, next, a.size() - 1);
        if (min_pos != next)
            swap(a[min_pos].salary, a[next].salary);
    }
}


void print(vector<employee>& a)
{
    for (int i = 0; i < a.size(); i++)
        cout << a[i].name << ", " << a[i].salary;
    cout << "\n";
}

int main()
{
    int empl;
    cout << "enter the number of employees:\n";
    cin >> empl;
    vector<employee> v(empl);
    for (int i = 0; i < empl; i++)
    {
        cout << "Enter the employee and the salary: " << endl;

        employee e; // create an employee
        cin >> e.name; // get name from user
        cin >> e.salary; // get salary from user

        v.push_back(e); // put employee into vector
    }
    print(v);
    selection_sort(v);
    cout << "_________________________" << endl;
    print(v);
    return 0;
}

這是輸出：

Enter the number of employees:
2
Enter the employee and the salary: 
John
60
Enter the employee and the salary: 
Ron
20
, 0, 0John, 60Ron, 20
_________________________
, 0, 0John, 20Ron, 60

Answer 1

我不確定您的問題是什么或期望什么，但是您只是在這里交換salary ：

swap(a[min_pos].salary, a[next].salary);

您想交換整個employee ：

swap(a[min_pos], a[next]);

編輯：現在，您編輯了問題所在，這是您看到的問題：

vector<employee> v(empl);
for (int i = 0; i < empl; i++)
{
    cout << "Enter the employee and the salary: " << endl;

    employee e; // create an employee
    cin >> e.name; // get name from user
    cin >> e.salary; // get salary from user

    v.push_back(e); // put employee into vector
}

在此循環之前，您將矢量初始化為員工人數，然后添加您所讀的員工。 因此，您最終得到的雇員數量是您期望的2倍，其中一半是垃圾。 要解決此問題，請聲明向量不同：

vector<employee> v;

還是不要push_back ：

v[i] = e;