日期、天转换函数

 1 #include<iostream>
 2 using namespace std;
 3 
 4 static int daytable[2][13] ={
 5     {0,31,28,31,30,31,30,31,31,30,31,30,31},
 6     {0,31,29,31,30,31,30,31,31,30,31,30,31}
 7 };
 8 //返回某年某月的某天是该年的第多少天
 9 int day_of_year(int year ,int month,int day)
10 {
11     int i,leap;
12     leap = ((year %4 ==0 && year%100 != 0 )||( year %400 == 0));
13     for ( i  = 1; i < month;i++)
14     {
15         day += daytable[leap][i];
16     }
17 
18     return day;
19 }
20 //返回某年的第多少天是该年的几月几号
21 void month_day(int year ,int yearday ,int  *pmonth , int *pday)
22 {
23     int i,leap;
24     leap = ((year %4 ==0 && year%100 != 0 )||( year %400 == 0));
25     for (i = 1; yearday > daytable[leap][i] ; i++)
26     {
27         yearday -= daytable[leap][i]; 
28     }
29     *pmonth = i;
30     *pday = yearday;
31 }
32 void main()
33 {
34     cout<<day_of_year(1988,8,2)<<endl;
35     int month,day;
36     month_day(1988,325,&month,&day);
37     cout<<month<<"月"<<day<<"号";
38     cout<<endl;
39 }