日期、天转换函数

#include<iostream>
using namespace std;

static int daytable[2][13] ={
    {0,31,28,31,30,31,30,31,31,30,31,30,31},
    {0,31,29,31,30,31,30,31,31,30,31,30,31}
};
//返回某年某月的某天是该年的第多少天
int day_of_year(int year ,int month,int day)
{
    int i,leap;
    leap = ((year %4 ==0 && year%100 != 0 )||( year %400 == 0));
    for ( i  = 1; i < month;i++)
    {
        day += daytable[leap][i];
    }

    return day;
}
//返回某年的第多少天是该年的几月几号
void month_day(int year ,int yearday ,int  *pmonth , int *pday)
{
    int i,leap;
    leap = ((year %4 ==0 && year%100 != 0 )||( year %400 == 0));
    for (i = 1; yearday > daytable[leap][i] ; i++)
    {
        yearday -= daytable[leap][i]; 
    }
    *pmonth = i;
    *pday = yearday;
}
void main()
{
    cout<<day_of_year(1988,8,2)<<endl;
    int month,day;
    month_day(1988,325,&month,&day);
    cout<<month<<"月"<<day<<"号";
    cout<<endl;
}