A difficult C program!

[LaoLiulaoliu]

I have wrote a c program,it is used for print date(from 20030101 to 20041231).
There is some bugs in my program,but I can not find it.
May be I need some help.Thanks for the people helping me!
The bug is different months show the mess day-count(june have 29 days,other months is the same)
The program as follows:


#include<stdio.h>
main()
{
int d[2]={0,1},m[2]={0,1},y[4]={2,0,0,3};
int year,month,day;

while(y[3]<5){
year=y[0]*1000+y[1]*100+y[2]*10+y[3];
month=1;
m[0]=0;m[1]=1;


while(month<12) {
month=m[0]*10+m[1];
d[0]=0;d[1]=1;

while(1) {
day=d[0]*10+d[1];
printf("%d%d%d%d%d%d%d%d\n",y[0],y[1],y[2],y[3],m[0],m[1],d[0],d[1]);
if(d[1]==9)
{d[1]=0;
d[0]++;}
else d[1]++;

if(month==1||3||5||7||8||10||12){
if(day==31) break;
}

if(month==4||6||9||11){
if(day==30) break;
}

if((year%4==0&&year%100!=0)||(year%400==0))
{if(day==29)break;}
else
if(day==28 )break;
}

if(m[1]==9)
{m[1]=0;
m[0]++;}
else m[1]++;

}


if(y[3]==9)
{y[3]=0;
y[2]++;}
else y[3]++;

}

}

[engineer]

sounds like school homework!

i'd recommend to use more braces. then you'll find the errors more easily.

[Klipt]

Put your code in code tags so the formatting doesn't disappear; it's easier to read.

The main problem is that you can't say

if (x == 0 || 1 || 2)
Since in C integer values are considered 'false' if 0 and 'true' otherwise, so you're saying "If x == 0, or 1, or 2" which will always be true since 1 is non-zero. You have to write it like

if (x == 0 || x == 1 || x == 2)

[Lster]

Yes, it would be easier to read if you indented the code and used braces.

[daniminas]

Like Klipt says, the solution, i think is to change:


if (x == 0 || 1 || 2)

and put:


if (x == 0 || x == 1 || x == 2)


;)

[LaoLiulaoliu]

thank you for all of you!

[Wim Sturkenboom]

You certainly have a complicated way of doing it; but OK, nobody knows all C functions


step 1
use mktime to calculate the number of seconds since 01-01-1970 for the first date (t1) and for the last date (t2)
step 2
increment t1 by the number of seconds in a day
step 3
use localtime to get year, month and day from t1
print it
step 4
goto to step 2 if t2>t1