C语言计算两日期之间的天数

C语言计算两日期之间的天数

代码如下：
#include
int mon[12]={31,28,31,30,31,30,31,31,30,31,30,31}; /*储存12个月的天数*/
void main()
{
int spec_year(int);
void scan(int *year,int *month,int *day);
long com_year(int y1,int y2);
int com_month(int y1,int m1,int y2,int m2);
int com_day(int y1,int m1,int d1,int y2,int m2,int d2);
int year1,month1,day1;
int year2,month2,day2;
long sum=0;
int k=0;
/*输入两个日期,做合法性检查*/
printf("Enter the first date,like 1988 11 30:");
scan(&year1,&month1,&day1);
printf("Enter the second date,like 1988 11 30:");
scan(&year2,&month2,&day2);
/*当输入的第一个日期比第二个日期大时,将二者对换*/
if((year1>year2)||((year1==year2)&&(month1>month2))||((year1==year2)&&(month1==month2)&&(day1>day2)))
{
int temp;
temp=year1;year1=year2;year2=temp;
temp=month1;month1=month2;month2=temp;
temp=day1;day1=day2;day2=temp;
}
/*计算两个日期之间的天数*/
sum+=com_year(year1,year2); /*计算两个年份之间的天数*/
sum+=com_month(year1,month1,year2,month2); /*计算两个月份之间的天数*/
sum+=com_day(year1,month1,day1,year2,month2,day2); /*计算两天之间的天数*/
/*输出*/
printf("There are %ld days between them.\n",sum);
}
void scan(int *year,int *month,int *day) /*输入日期函数,合法性判断*/
{
int k=0;
do
{
if(k!=0)
printf("\nWrong date!\n");
k++;
/*printf("Please write down the day,like 1988 11 30:");*/
scanf("%d%d%d",year,month,day);
if(spec_year(*year))
mon[1]=29;
}while(*day>mon[*month-1]||*month>13||*year3000);
mon[1]=28;
}
long com_year(int y1,int y2) /*计算两个年份之间的天数*/
{
int i;
long sum=0;
for(i=y1+1;i