Jan 30, 2012

K & R C Programs Exercise 5-9.

K and R C, Solution to Exercise 5-9:
K and R C Programs Exercises provides the solution to all the exercises in the C Programming Language (2nd Edition). You can learn and solve K&R C Programs Exercise.
C program to , Rewrite the routines of K & R C Programs Exercise 5-8 day_of_year and month_day with pointers instead of indexing.Read more about C Programming Language .

/***********************************************************
* You can use all the programs on  www.c-program-example.com
* for personal and learning purposes. For permissions to use the
* programs for commercial purposes,
* contact info@c-program-example.com
* To find more C programs, do visit www.c-program-example.com
* and browse!
* 
*                      Happy Coding
***********************************************************/

#include <stdio.h>

static char daytab[2][13] =  {
  {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
  {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
};



int day_of_year(int year, int month, int day)
{
 int i, leap;
 char *p;

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

 /* Set `p' to point at first month in the correct row. */
 p = &daytab[leap][1];

 /* Move `p' along the row, to each successive month. */
 for (i = 1; i < month; i++) {
  day += *p;
  ++p;
 }
 return day;
}

void month_day(int year, int yearday, int *pmonth, int *pday)
{
 int i, leap;
 char *p;

 leap = (year%4 == 0 && year%100 != 0) || year%400 == 0;
 p = &daytab[leap][1];
 for (i = 1; yearday > *p; i++) {
  yearday -= *p;
  ++p;
 }
 *pmonth = i;
 *pday = yearday;
}


int main(void)
{
 int year, month, day, yearday;

 year = 2012;
 month = 7;
 day = 9;
 printf("The date is: %d-%02d-%02d\n", year, month, day);
 printf("day_of_year: %d\n", day_of_year(year, month, day));



 yearday = 61; /* 2012-03-01 */
 printf("Yearday is %d\n", yearday);
 month_day(year, yearday, &month, &day);
 printf("month_day_pointer: %d %d\n", month, day);

 return 0;
}


Read more c programs 
C Basic
C Strings
K and R C Programs Exercise
You can easily select the code by double clicking on the code area above.

To get regular updates on new C programs, you can

You can discuss these programs on our Facebook Page. Start a discussion right now,

our page!

Share this program with your Facebook friends now! by liking it


(you can send this program to your friend using this button)

Like to get updates right inside your feed reader? Grab our feed!

To browse more C Programs visit this link