C :

#include <stdio.h>
int main ()
{
	int i;
	scanf("%d",&i);
	switch (i)
	{
	case 0:  printf("Sunday\n");break;
	case 1:  printf("Monday\n");break;
	case 2:  printf("Tuesday\n");break;
	case 3:  printf("Wednesday\n");break;
	case 4:  printf("Thursday\n");break;
	case 5:  printf("Friday\n");break;
	case 6:  printf("Satursday\n");break;
	default: printf("Error\n");
	}
	return 0;
}

C++ :

#include<iostream>

using namespace std;

int main()
{
	int day;
	cin >> day;
	switch(day)
	{
	case 0:
		cout << "Sunday";
		break;
	case 1:
		cout << "Monday";
		break;
	case 2:
		cout << "Tuesday";
		break;
	case 3:
		cout << "Wednesday";
		break;
	case 4:
		cout << "Thursday";
		break;
	case 5:
		cout << "Friday";
		break;
	case 6:
		cout << "Saturday";
		break;
	default:
		cout << "Error";
		break;
	}
	return 0;
}