C++:显示每年的各月份第一天是星期几

编写一个程序，提示用户输入一个年份以及这一年中第一天是星期几，

然后，输出每个月的第一天是星期几。

#include <iostream>
using namespace std;

int main()
{
  cout << "Enter a year: ";
  int year;
  cin >> year;

  cout << "Enter the first day of the year: ";
  int firstDay;
  cin >> firstDay;

  int numberOfDaysInMonth = 0;

  // Display calendar for each month
  for (int month = 1; month <= 12; month++)
  {
    // Display Calendar title
    switch (month)
    {
      case 1:
        cout << "January 1, " << year << " is ";
        numberOfDaysInMonth = 31;
      break;
      case 2:
  &nbs