一年的第几天

#include
#include
#include

#define TRUE  1
#define FALSE 0
int toint(char *s);
int isleap(int year);
int check(int year,int month,int day);
void func(int year,int month,int day);

int main(int argc, char **argv)
{
 int days[]={0,31,28,31,30,31,30,31,31,30,31,30,31};
 int day,y,m,d;

 if(4!=argc)
 {
  printf("please input year,month,day: ");
  scanf("%d %d %d", &y, &m, &d);
 }
 else
 {
  y = toint(argv[1]);
  m = toint(argv[2]);
  d = toint(argv[3]);
 }

 if(check(y,m,d))
 {
  printf("%d %d %d\n", y,m,d);
  func(y,m,d);
 }

 return 0;
}

int toint(char *s)
{
 int ret=0;
 char *tmp=s;
 while('\0'!=*tmp)
 {
  ret=ret*10+*tmp-'0';
 }
 return ret;
}

int isleap(int year)
{
 if(((year%4==0)&&(year%100==0))||(year%400==0))
 {
  return TRUE;
 }
 return FALSE;
}
int check(int year,int month,int day)
{
 int days[]={0,31,28,31,30,31,30,31,31,30,31,30,31};
 if(isleap(year))
 {
  days[2]=29;
 }
 if(year<0)
 {
  return FALSE;
 }
 if(month<1||month>12)
 {
  return FALSE;
 }
 if(day>days[month])
 {
  return FALSE;
 }
 return TRUE;
}

void func(int y,int m,int d)
{
 int i, day=0;
 int days[]={0,31,28,31,30,31,30,31,31,30,31,30,31};
 if(isleap(y))
 {
  days[2]=29;
 }
 for(i=0;i {
  day+=days[i];
 }
 day+=d;
 printf("%d %d %d is the %d day.\n", y,m,d,day);
}