Assistance in fixing an almost-complete program?

[birdwalkr]

So this program is supposed to take the day, month and year and be able to show you the weekday of that particular date. Problem is I always get the output 84 for some reason. Don't understand where that number is coming from or what I necessarily need to fix?

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

int month (int mm)
{
    if (mm == 1)return 13;
    if (mm == 2)return 14;
    if (mm == 3)return 3;
    if (mm == 4)return 4;
    if (mm == 5)return 5;
    if (mm == 6)return 6;
    if (mm == 7)return 7;
    if (mm == 8)return 8;
    if (mm == 9)return 9;
    if (mm == 10)return 10;
    if (mm == 11)return 11;
    if (mm == 12)return 12;
}

int weekday_number (int wn)
{
    int mm;
    int d;
    int y;
    wn=(d+5+(((26*(mm + 1))/10)+((5*(y%100))/4)+((21*(y/100))/4)))%7;
    return wn;
}

int main()
{
    int d;
    int mm;
    int y;
    int wn;
    cout << "Please enter a date (Format: month/day/year) and I'll compute the weekday: " << endl;
    cout << "Date Example: 01/20/2012" << endl;
    cin >> mm >> d >> y;
    cout << wn << endl;
    if (wn == 0)
    {
    cout << "Monday";
    }
    else if (wn == 1)
    {
    cout << "Tuesday";
    }
    else if (wn == 2)
    {
    cout << "Wednesday";
    }
    else if (wn == 3)
    {
    cout << "Thursday";
    }
    else if (wn == 4)
    {
    cout << "Friday";
    }
    else if (wn == 5)
    {
    cout << "Saturday";
    }
    else if (wn == 6)
    {
    cout << "Sunday";
    }
    else
    {
    cout << "Error Occured" << endl;
    }
    system ("pause");
    return 0;
}

[TheJJJunk]

You aren't calling your functions in the main function.

[birdwalkr]

How do you mean? I thought by using an if statement and typing "wn" it would take the result from the function?

[TheJJJunk]

In your main function,

int d;
 int mm;
    int y;
    int wn;
    cout << "Please enter a date (Format: month/day/year) and I'll compute the weekday: " << endl;
    cout << "Date Example: 01/20/2012" << endl;
    cin >> mm >> d >> y;
    wn = weekday_number(d, mm, y);
    cout << wn << endl;
    if (wn == 0)
    {
    cout << "Monday";
    }
    else if (wn == 1)
    {
    cout << "Tuesday";
    }
    else if (wn == 2)
    {
    cout << "Wednesday";
    }
    else if (wn == 3)
    {
    cout << "Thursday";
    }
    else if (wn == 4)
    {
    cout << "Friday";
    }
    else if (wn == 5)
    {
    cout << "Saturday";
    }
    else if (wn == 6)
    {
    cout << "Sunday";
    }
    else
    {
    cout << "Error Occured" << endl;
    }
    system ("pause");
    return 0;
}

In your int weekday_number,

int weekday_number(int d, int mm, int y)
{
  int mm;
    int d;
    int y;
  return (   (d+5+(((26*(month(mm) + 1))/10)+((5*(y%100))/4)+((21*(y/100))/4)))%7   );
  
}

[birdwalkr]

Oh ok thanks I see what you did! I'm new to all this and these things tend to fly by me.

[TheJJJunk]

bottom line is that functions won't 'activate' unless another function calls them.