THIS IS C++ PROGRAMMING:

--I need some assistance on implementing functions (They will be italized)

int main()

{

char choice;

int day, month, year;

do

{

system("CLS");

menu();// display menu by calling menu function

cout << " \tPlease enter your choice: ";// ask user to enter his/her choice on menu

cin >> choice;// get user's choice

switch (choice)

{

case '1': // will query a date.

get_input(month, day, year);

print_calendar(month, day, year);// print out the day of week of specified date

break;

case '2': // print out the calendar of a given month.

get_input(month, year);

print_calendar(month, year);//print out the calendar of specified month

break;

case '3': // print out the calendar of a given year.

get_input(year);

print_calendar(year);// print out the calendar of specified year

break;

case '4': // print out the calendar of specified year to yourname.txt file

// you implement this ******************

break;

case '5': // quit the program.

cout << " \tThank you for using calendar program! "; // you may replace your name here

break;

default: // other choices that are not the options on menu.

cout << "Error, no such choice. Please choose from Menu. ";//print out error message

break;

}

cout << " \t";

system("pause");

} while (choice != '5');

return 0;

}

// you implement all function stubs here

void menu()

{

cout << " \t***************************************************";

cout << " \t* Menu *";

cout << " \t* 1. Query a date *";

cout << " \t* 2. Print calendar of a given month *";

cout << " \t* 3. Print calendar of a given year *";

// add one more options here. Notice that the quit option becomes option 5 now

cout << " \t* 5. Quit *";

cout << " \t***************************************************";

}

void get_input(int& month, int& day, int& year)

{

cout << " \tEnter the date in form of mm dd yyyy: ";

cin >> month >> day >> year;

while (!isValid(month, day, year)) // as long as the date is NOT valid, keep asking to reenter the date

{

cout << " \tThe date you entered is NOT valid. Please reenter a valid date: ";

cin >> month >> day >> year;

}

}

void get_input(int& month, int& year)

{

cout << " \tEnter the month and year in form of mm yyyy: ";

cin >> month >> year;

while (!isValid(month, year)) // as long as the month is NOT valid, keep asking to reenter the month

{

cout << " \tThe month you entered is NOT valid. Please reenter a valid month: ";

cin >> month >> year;

}

}

void get_input(int& year)

{

cout << " \tEnter the year as yyyy: ";

cin >> year;

while (!isValid(year)) // as long as the year is NOT valid, keep asking to reenter the year

{

cout << " \tThe year you entered is NOT valid. Please reenter a valid year: ";

cin >> year;

}

}

bool isValid(int month, int day, int year)

{

bool result = true; // temporary assume that the result is true

switch (month) // update result based on day

{

case 1: case 3: case 5: case 7: case 8: case 10: case 12:

result = day >= 1 && day <= 31;

break;

case 4: case 6: case 9: case 11:

result = day >= 1 && day <= 30;

break;

case 2:

if (isLeapYear(year))

result = day >= 1 && day <= 29;

else

result = day >= 1 && day <= 28;

break;

}

return result && isValid(month, year); // day is valid and (month and year are valid)

}

bool isValid(int month, int year)

{

return month >= 1 && month <= 12 && year > 1582; // month is between 1 and 12 and year is later than 1582

}

bool isValid(int year)

{

return year > 1582; // year is later than 1582

}

bool isLeapYear(int year)

{

return ((year % 400 == 0) || (year % 4 == 0 && year % 100 != 0));

}

int getCenturyValue(int year)

{

return 2 * (3 - (year / 100) % 4);

}

int getYearValue(int year)

{

return year % 100 + year % 100 / 4;

}

int getMonthValue(int month, int year)

{

int result;

switch (month)

{

case 1:

if (isLeapYear(year))

result = 6;

else result = 0;

break;

case 2:

if (isLeapYear(year))

result = 2;

else

result = 3;

break;

case 3: case 11:

result = 3;

break;

case 4: case 7:

result = 6;

break;

case 5:

result = 1;

break;

case 6:

result = 4;

break;

case 8:

result = 2;

break;

case 9:case 12:

result = 5;

break;

default: // case 10

result = 0;

break;

}

return result;

}

int dayOfWeek(int month, int day, int year)

{

if (!isValid(month, day, year)) return -1;

return (getCenturyValue(year) + getMonthValue(month, year) + getYearValue(year) + day) % 7;

}

void print_calendar(int month, int day, int year)

{

if (!isValid(month, day, year)) { // if the date is NOT valid, print out error message and return

cout << " \tThe date is NOT valid!";

return;

}

cout << " \t" << monthName(month) << " " << day << " , " << year << " is " << dayOfWeek(dayOfWeek(month, day, year));

}

void print_calendar(int month, int year)

{

if (!isValid(month, year)) { // if the month is NOT valid, print out error message and return

cout << " \tThe month is NOT valid!";

return;

}

// print out the month and year

cout << " \t " << monthName(month) << ", " << year << endl;

// print out day names

cout << " \t SUN MON TUE WED THU FRI SAT \t";

int spaceCount = dayOfWeek(month, 1, year);

// print out spaces

for (int i = 0; i < spaceCount; i++)

cout << setw(4) << "";

// calculate the days in the month

int days = daysInMonth(month, year);

// print out all days

for (int j = 1; j <= days; j++)

{

cout << setw(4) << j;

if ((spaceCount + j) % 7 == 0) // go to new line for a new week

cout << " \t";

}

}

void print_calendar(int year)

{

if (!isValid(year)) { // if the year is NOT valid, print out error message and return

cout << " \tThe year is NOT valid!";

return;

}

for (int i = 1; i <= 12; i++) // print out 12 month calendar

{

print_calendar(i, year); // print out ith month

cout << endl;

}

}

string monthName(int month)

{

string result;

switch (month)

{

case 1:

result = "January";

break;

case 2:

result = "February";

break;

case 3:

result = "March";

break;

case 4:

result = "April";

break;

case 5:

result = "May";

break;

case 6:

result = "June";

break;

case 7:

result = "July";

break;

case 8:

result = "August";

break;

case 9:

result = "September";

break;

case 10:

result = "October";

break;

case 11:

result = "November";

break;

case 12:

result = "December";

break;

default:

result = "Not valid month";

break;

}

return result;

}

string dayOfWeek(int day)

{

string result;

switch (day)

{

case 0:

result = "Sunday";

break;

case 1:

result = "Monday";

break;

case 2:

result = "Tuesday";

break;

case 3:

result = "Wednesday";

break;

case 4:

result = "Thursday";

break;

case 5:

result = "Friday";

break;

case 6:

result = "Saturday";

break;

default:

result = "Invalid date";

break;

}

return result;

}

int daysInMonth(int month, int year)

{

int result;

switch (month)

{

case 1: case 3: case 5: case 7: case 8: case 10: case 12:

result = 31;

break;

case 4: case 6: case 9: case 11:

result = 30;

break;

case 2:

if (isLeapYear(year))

result = 29;

else result = 28;

break;

default:

result = -1;

break;

}

return result;

}

bool print_calendar(int year, string fileName)

{

// if year is not valid, print out error message and return false

// declare a local ofstream variable and open file to write

// if file open failed, print out error message and return false

// use for loop to print out 12 months to the file

// close file

// return true

}

void print_calendar(int month, int year, ofstream& output)

{

// if the month is NOT valid, print out error message and return

// print out the month and year

// print out day names

// calculate spaces before the first day of the month

// print out spaces

// calculate the days in the month

// print out all days, using a for loop

// two more new lines

// Note this function is very similar to the one print to screen

}