平均2个函数

当我运行这段代码时，我似乎一直在偏离平均值，并想知道是否有人有任何建议。尝试过的一个例子是，只做了5名员工，他们都错过了5天，平均值一直保持在15天，我算错了吗？再次感谢您的帮助。我发布了完整的代码，以防它不是我试图让它尽可能整洁的功能，所以很抱歉，如果它有点乱，我已经编程了不到一个月了。

#include<iostream>
using namespace std;
function prototypes
//return type: void
//parameter type: 1 int by refrence
//purpose: This function asks the user for the number of employees in the company.
void GetNumEmployees(int&);
//return type: int
//parameter type: 1 int
//Purpose: The function should as the user to enter the number of days each employee missed during the past year
int TotalDaysMissed(int);
//return type: float
//parameters: 2 int
//Purpose: Returns the average of total number of days missed for all employees in the company during the year
float AverageDaysMissed(int, int);
int main()
{
    //Declare and Initilize Variables
    int empnum = 0, daysmissed = 0 ;
    float averagedays = 0.0 ;
    GetNumEmployees(empnum) ;
    daysmissed = TotalDaysMissed(empnum)    ;
    averagedays = AverageDaysMissed(empnum, daysmissed) ;
    cout<<"The Average Work Days your Employees Missed is "<<averagedays<<endl ;
    return 0;
}
//function definitions
void GetNumEmployees(int &emp)
{
    do
    {
        cout<<"Enter the number of Employees in the company: ";
        cin>>emp ;
        if(emp < 1)
            cout<<"Invalid. Cannot be Less than 1nn";
    }
    while (emp < 1) ;
}
int TotalDaysMissed(int empn)
{
    int daysmissed = 0 ;
    int total = 0 ;
    for(int n = empn; n > 0  ; n--)
    {
        do
        {
            cout<<"How Many days did Employee "<<n<< " miss? " ;
            cin>>daysmissed ;
            total += daysmissed;
            if(daysmissed < 0)
                cout<<"Invalid days must be a Positive Numbernn";
        }
        while(daysmissed < 0) ;
    }
    return total;
}
float AverageDaysMissed(int empn, int daystotal)
{
    float average = 0.0     ;
    average = (empn + daystotal) / 2.0 ;
    return average;
}