Thread: Debugging driving me crazy

This section of code just doesn't seem to work for me. It skips the if block (in bold) when I know the statement is true.

Code:

double convert_to_julian(int *p_year, int *p_mon, int *p_day){
  int a = 0, b = 0, c = 0, d = 0;

  if(*p_mon == 1 || *p_mon == 2){
    *p_year -= 1;
    *p_mon += 12;
  }
   // At this point I know that year is 1994 month is 2 and day is 1
  if((*p_year >= 1582) && (*p_mon >= OCT) && (*p_day >= 15)){
    a = (*p_year / 100);
    b = (2 - a) + (a / 4);
  }
  else{
    b = 0;
  }

  .
  .
  .

But it does work if I remove the (*p_day >= 15) condition.
There must be something I'm forgetting



[edit]
omg I just realised my problem. sorry for wasting time.
the answer was this

Code:

if((*p_year > 1582) || (*p_year == 1582) && (*p_mon >= OCT) && (*p_day >= 15)){

Furthermore, I would rather expect that block of statements to be skipped if month is 2 (assuming OCT is defined as 10) and/or day is 1. When you shake mathematics really hard, it turns out that 2<10 and 1<15.

Originally Posted by Codeplug

>> nevermind anyway
Well, I can't "nevermind" misinformation - the logic is identical.

Work it out for yourself: Operator Precedence and Associativity

gg

Huh?

Let's try them for today:

Code:

#include <stdio.h>

int main()
{
  int mon = 7;
  int day = 7;
  int year = 2005;

  printf("For mon = %d, day = %d, year = %d\n\n", mon, day, year);
  /* algorithm 1 */
  printf("Algorithm 1 says ");
  if((year >= 1582) && (mon >= 10) && (day >= 15)){
    printf("true\n");
  }
  else {
    printf("false\n");
  }

  /* algorithm 2 */
  printf("Algorithm 2 says ");
  if((year > 1582) || (year == 1582) && (mon >= 10) && (day >= 15)){
    printf("true\n");
  }
  else {
    printf("false\n");
  }
  return 0;
}

[edit]
[edit]
Previously edited edit remarks removed.
[/edit]
[/edit]

Regards,

Dave

And shouldn't the check be something like this?

Code:

int bar(int year, int month, int day)
{
   return year > 1582 || (year == 1582 && (month > 10 || (month == 10 && day >= 15)));
}

Otherwise it would skip the first 14 days of November and December in 1582.

Originally Posted by Dave_Sinkula

And shouldn't the check be something like this?

Right

(But note that I already knew that. I was just pointing out that the two expressions in prior posts had different values. That's my story and I'm sticking to it. --- But I had added some incorrect remarks that I have now removed.)

Regards,

Dave