Writea c program to print the day for an input of date month and year?

Answer 1

#include<iostream>

#include<string>

#include<ctime>

using namespace std;

std::tm input_date()

{

while (true)

{

cout << "Enter date (dd/mm/yyyy): ";

string input;

getline (cin, input);

size_t d, m, y;

int n = sscanf (input.c_str(), "%u/%u/%u", &d, &m, &y);

if (n!=3)

cout << input << " is not a valid date." << endl;

else

{

tm date;

memset (&date, 0, sizeof(tm));

date.tm_isdst = -1;

date.tm_mday = d;

date.tm_mon = m-1;

date.tm_year = y-1900;

return date;

}

}

}

int main()

{

tm date = input_date();

time_t tt = mktime (&date);

date = *localtime(&tt);

switch (date.tm_wday)

{

case (0): std::cout << "Sunday"; break;

case (1): std::cout << "Monday"; break;

case (2): std::cout << "Tuesday"; break;

case (3): std::cout << "Wednesday"; break;

case (4): std::cout << "Thursday"; break;

case (5): std::cout << "Friday"; break;

case (6): std::cout << "Saturday"; break;

}

std::cout << std::endl;

}

Answer 2

#include<stdio.h>

#include<stdlib.h>

int main()

{

int d,m,y,year,month,day,i,n;

printf("Enter how many times you want to run this program : ");

scanf("%d",&n);

for(i=1;i<=n;i++)

{

printf("Enter the date : ");

scanf("%d%d%d",&d,&m,&y);

if( d>31 m>12 (y<1900 y>=2000) )

{

printf("INVALID INPUT");

exit(0);

}

year = y-1900;

year = year/4;

year = year+y-1900;

switch(m)

{

case 1:

case 10:

month = 1;

break;

case 2:

case 3:

case 11:

month = 4;

break;

case 7:

case 4:

month = 0;

break;

case 5:

month = 2;

break;

case 6:

month = 5;

break;

case 8:

month = 3;

break;

case 9:

case 12:

month = 6;

break;

}

year = year+month;

year = year+d;

day = year%7;

switch(day)

{

case 0:

printf("Day is SATURDAY\n");

break;

case 1:

printf("Day is SUNDAY\n");

break;

case 2:

printf("Day is MONDAY\n");

break;

case 3:

printf("Day is TUESDAY\n");

break;

case 4:

printf("Day is WEDNESDAY\n");

break;

case 5:

printf("Day is THURSDAY\n");

break;

case 6:

printf("Day is FRIDAY\n");

break;

}

}

getchar();

getchar();

return 0;

}

Answer 3

#include<iostream>

#include<iomanip>

#include<string>

#include<sstream>

#include<cassert>

using std::cout;

using std::cin;

using std::endl;

using std::setw;

using std::string;

using std::stringstream;

#ifndef NDEBUG

#define assert_year(year) do { assert (1900 <= (year)); } while(0)

#define assert_month(month) do { assert ((month) && ((month) <= 12)); } while(0)

#define assert_day(day) do { assert ((day) && ((day) <= 31)); } while(0)

#else

#define assert_year(year) ((void)0)

#define assert_month(month) ((void)0)

#define assert_day(day) ((void)0)

#endif NDEBUG

bool is_leap_year (size_t year)

{

assert_year (year);

if (year%4) return false; // If not a multiple of 4 then a common year.

if (year%100) return true; // Otherwise, if not a multiple of 100 then a leap year.

if (year%400) return false; // Otherwise, if not a multiple of 400 then a common year.

return true; // Otherwise, a leap year.

}

size_t days_in_month (size_t month, size_t year)

{

assert_month (month);

switch (month)

{

case 2:

return is_leap_year (year) ? 29 : 28;

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

return 30;

}

return 31;

}

size_t day_of_year (size_t day, size_t month, size_t year)

{

assert_day (day);

assert_day (month);

size_t days = day;

while (--month)

days += days_in_month (month, year);

return days;

}

size_t days_in_previous_years (size_t year)

{

assert_year (year);

size_t days = 0;

while (1900 < --year)

days += is_leap_year (year) ? 366 : 365;

return days;

};

size_t days_since_epoch (size_t day, size_t month, size_t year)

{

// Epoch is 1st January 1900

return days_in_previous_years (year) + day_of_year (day, month, year);

}

size_t day_of_week (size_t day, size_t month, size_t year)

{

return days_since_epoch (day, month, year) % 7;

}

void centre (const std::string& s, const size_t width)

{

unsigned pad = (width-s.size())/2;

unsigned pos;

for (pos=0; pos<pad; ++pos)

cout << ' ';

cout << s;

for (pos=0; pos<pad; ++pos)

cout << ' ';

}

void centre (const unsigned n, const size_t width)

{

stringstream ss;

ss << n;

centre (ss.str(), width);

}

void print_calendar (size_t year)

{

const unsigned q_div = 32;

// print the year

centre (year, q_div*3);

cout << '\n' << endl;

for (unsigned quarter=0; quarter<4; ++quarter)

{

// print the month

switch (quarter)

{

case (0): centre ("January", q_div); centre ("February", q_div); centre ("March", q_div); break;

case (1): centre ("April", q_div); centre ("May", q_div); centre ("June", q_div); break;

case (2): centre ("July", q_div); centre ("August", q_div); centre ("September", q_div); break;

case (3): centre ("October", q_div); centre ("November", q_div); centre ("December", q_div); break;

}

cout << '\n' << endl;

// print the day of the week for each month

for (unsigned week=0; week<3; ++week)

centre ("Mo Tu We Th Fr Sa Su", q_div);

cout << endl;

cout << ' ';

// determine start day and count of days in each month

unsigned start[3], days[3], day[3]={0,0,0};

for (unsigned m=0; m<3; ++m)

{

unsigned month=quarter*3+m+1;

start[m] = day_of_week (1, month, year);

days[m] = days_in_month (month, year);

// print first week

for (unsigned i=0; i<start[m]; ++i)

cout << setw(4) << ' ';

while (day[m]<=6-start[m])

cout << setw(4) << ++day[m];

cout << setw(4) << ' ';

}

cout << endl;

// print remaining weeks

for (unsigned w=0; w<5; ++w)

{

cout << ' ';

for (unsigned m=0; m<3; ++m)

{

for (unsigned d=0; d<7; ++d)

{

if (day[m]<days[m])

cout << setw(4) << ++day[m];

else

cout << setw(4) << ' ';

}

cout << setw(4) << ' ';

}

cout << endl;

}

cout << endl;

}

cout << endl;

}

size_t ask (string prompt)

{

for (;;)

{

cout << prompt;

string input;

cin >> input;

stringstream ss;

ss << input;

size_t reply;

if (ss >> reply)

return reply;

cout << "Invalid input.\n";

}

}

int main (void)

{

while (true)

{

size_t year = ask ("Enter a year (>= 1900, 0 to exit): ");

if (!year)

break;

if (year < 1900)

{

cout << "Invalid year." << endl;

continue;

}

print_calendar (year);

}

}

Answer 4

#include

#include

#include

#include

#include

using std::cout;

using std::cin;

using std::endl;

using std::setw;

using std::string;

using std::stringstream;

#ifndef NDEBUG

#define assert_year(year) do { assert (1900 <= (year)); } while(0)

#define assert_month(month) do { assert ((month) && ((month) <= 12)); } while(0)

#define assert_day(day) do { assert ((day) && ((day) <= 31)); } while(0)

#else

#define assert_year(year) ((void)0)

#define assert_month(month) ((void)0)

#define assert_day(day) ((void)0)

#endif NDEBUG

bool is_leap_year (size_t year)

{

assert_year (year);

if (year%4) return false; // If not a multiple of 4 then a common year.

if (year%100) return true; // Otherwise, if not a multiple of 100 then a leap year.

if (year%400) return false; // Otherwise, if not a multiple of 400 then a common year.

return true; // Otherwise, a leap year.

}

size_t days_in_month (size_t month, size_t year)

{

assert_month (month);

switch (month)

{

case 2:

return is_leap_year (year) ? 29 : 28;

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

return 30;

}

return 31;

}

size_t day_of_year (size_t day, size_t month, size_t year)

{

assert_day (day);

assert_day (month);

size_t days = day;

while (--month)

days += days_in_month (month, year);

return days;

}

size_t days_in_previous_years (size_t year)

{

assert_year (year);

size_t days = 0;

while (1900 < --year)

days += is_leap_year (year) ? 366 : 365;

return days;

};

size_t days_since_epoch (size_t day, size_t month, size_t year)

{

// Epoch is 1st January 1900

return days_in_previous_years (year) + day_of_year (day, month, year);

}

size_t day_of_week (size_t day, size_t month, size_t year)

{

return days_since_epoch (day, month, year) % 7;

}

void centre (const std::string& s, const size_t width)

{

unsigned pad = (width-s.size())/2;

unsigned pos;

for (pos=0; pos

cout << ' ';

cout << s;

for (pos=0; pos

cout << ' ';

}

void centre (const unsigned n, const size_t width)

{

stringstream ss;

ss << n;

centre (ss.str(), width);

}

void print_calendar (size_t year)

{

const unsigned q_div = 32;

// print the year

centre (year, q_div*3);

cout << '\n' << endl;

for (unsigned quarter=0; quarter<4; ++quarter)

{

// print the month

switch (quarter)

{

case (0): centre ("January", q_div); centre ("February", q_div); centre ("March", q_div); break;

case (1): centre ("April", q_div); centre ("May", q_div); centre ("June", q_div); break;

case (2): centre ("July", q_div); centre ("August", q_div); centre ("September", q_div); break;

case (3): centre ("October", q_div); centre ("November", q_div); centre ("December", q_div); break;

}

cout << '\n' << endl;

// print the day of the week for each month

for (unsigned week=0; week<3; ++week)

centre ("Mo Tu We Th Fr Sa Su", q_div);

cout << endl;

cout << ' ';

// determine start day and count of days in each month

unsigned start[3], days[3], day[3]={0,0,0};

for (unsigned m=0; m<3; ++m)

{

unsigned month=quarter*3+m+1;

start[m] = day_of_week (1, month, year);

days[m] = days_in_month (month, year);

// print first week

for (unsigned i=0; i

cout << setw(4) << ' ';

while (day[m]<=6-start[m])

cout << setw(4) << ++day[m];

cout << setw(4) << ' ';

}

cout << endl;

// print remaining weeks

for (unsigned w=0; w<5; ++w)

{

cout << ' ';

for (unsigned m=0; m<3; ++m)

{

for (unsigned d=0; d<7; ++d)

{

if (day[m]

cout << setw(4) << ++day[m];

else

cout << setw(4) << ' ';

}

cout << setw(4) << ' ';

}

cout << endl;

}

cout << endl;

}

cout << endl;

}

size_t ask (string prompt)

{

for (;;)

{

cout << prompt;

string input;

cin >> input;

stringstream ss;

ss << input;

size_t reply;

if (ss >> reply)

return reply;

cout << "Invalid input.\n";

}

}

int main (void)

{

while (true)

{

size_t year = ask ("Enter a year (>= 1900, 0 to exit): ");

if (!year)

break;

if (year < 1900)

{

cout << "Invalid year." << endl;

continue;

}

print_calendar (year);

}

}