[OPPD] 计算两个日期之间相距天数

[OPPD] 计算两个日期之间相距天数

#

// created by ztwaker on 2006-8-24
// Used for: count days
// No guarantees offered. Constructive comments to [email protected]

// 需求：计算两个日期之间相距天数。
// 应用：倒计时等

#include <iostream>
#include <algorithm>
namespace date { //#define min(a, b) (((a) > (b)) ? (b) : (a)) //#define max(a, b) (((a) > (b)) ? (a) : (b))  class Bad_date {}; // exception throw  class Bad_year : public Bad_date {}; class Bad_month : public Bad_date {}; class Bad_day : public Bad_date {};     static const int this_year = 2006; inline bool leapyear(int year) { //if (year > this_year) // throw Bad_year();  return ((year % 100==0) ? (year % 400==0) : (year % 4==0)); } inline int yday(int year) { //if (year > this_year) // throw Bad_year();  return (365 + leapyear(year)); } inline int mday(int month, int year) { switch(month) { case 1: case 3: case 5: case 7: case 8: case 10: case 12: return 31; case 4: case 6: case 9: case 11: return 30; case 2: return 28 + leapyear(year); default: throw Bad_month(); } throw Bad_month(); } class Date{ int y, m, d; public:
		Date(int year, int month, int day) { // check year/month/day available  if (0 == year) throw Bad_year(); if (1 > month || 12 < month) throw Bad_month(); if (1 > day || mday(month, year) < day) throw Bad_day();
			
			y = year; m = month; d = day; }
		Date(const Date& rhs) { this->y = rhs.year(); this->m = rhs.month(); this->d = rhs.day(); }		
		Date& operator=(const Date& rhs) { if (rhs == (*this)) return (*this); this->y = rhs.year(); this->m = rhs.month(); this->d = rhs.day(); return (*this); } int year () const { return y; } int month() const { return m; } int day () const { return d; } int passday() const { int dpass = 0; for (int i = 1; i != m; ++i) {
				dpass += mday(i, y); } return (dpass + d); } friend std::ostream& operator<<(std::ostream& os, const Date& rhs); friend bool operator==(const Date& lhs, const Date& rhs); friend bool operator!=(const Date& lhs, const Date& rhs); friend bool operator< (const Date& lhs, const Date& rhs); friend bool operator> (const Date& lhs, const Date& rhs); friend bool operator<=(const Date& lhs, const Date& rhs); friend bool operator>=(const Date& lhs, const Date& rhs); friend int  distant(const Date& lhs, const Date& rhs); }; inline std::ostream& operator<<(std::ostream& os, const Date& rhs) { return (os << rhs.y << "-" << rhs.m << "-" << rhs.d); } inline bool operator==(const Date& lhs, const Date& rhs) { return (lhs.y == rhs.y && lhs.m == rhs.m && lhs.d == rhs.d); } inline bool operator!=(const Date& lhs, const Date& rhs) { return (!(lhs==rhs)); } inline bool operator<(const Date& lhs, const Date& rhs) { // compare year  if (lhs.y < rhs.y) { return true; } else if (lhs.y == rhs.y) { // compare month  if (lhs.m < rhs.m) { return true; } else if (lhs.m == rhs.m) { // compare day  if (lhs.d < rhs.d) return true; else return false; } return false; } return false; } inline bool operator>(const Date& lhs, const Date& rhs) { // compare year  if (lhs.y > rhs.y) { return true; } else if (lhs.y == rhs.y) { // compare month  if (lhs.m > rhs.m) { return true; } else if (lhs.m == rhs.m) { // compare day  if (lhs.d > rhs.d) return true; else return false; } return false; } return false; } inline bool operator<=(const Date& lhs, const Date& rhs) { return (!(lhs>rhs)); } inline bool operator>=(const Date& lhs, const Date& rhs) { return (!(lhs<rhs)); } int distant(const Date& lhs, const Date& rhs) { int distance = 0; const int lowyear = std::min(lhs.y, rhs.y); const int highyear = std::max(lhs.y, rhs.y); for (int yn = lowyear; yn != highyear; ++yn) {
			distance += yday(yn); } return (
			distance - std::min(lhs, rhs).passday() + std::max(lhs, rhs).passday() ); } } // end of namespace date void test() { try {
		date::Date today(2006, 1, 29); // 丙戌年春节 		date::Date deadline(2007, 2, 18); // 丁亥年春节 		std::cout << "From "<< today << " to " << deadline << " is ";
		std::cout << date::distant(today, deadline) << " days left.\n"; } catch (date::Bad_year) {
		std::cout << "Bad year" << std::endl; } catch (date::Bad_month) {
		std::cout << "Bad month" << std::endl; } catch (date::Bad_day) {
		std::cout << "Bad day" << std::endl; } catch (date::Bad_date) {
		std::cout << "Bad date" << std::endl; } } int main() {
    test(); return 0; }