c++ - 获取两天之间的交易日数

Question

我正在尝试获取两个日期之间的交易日期数量，这将只排除周末并且不会考虑任何假期。我正在使用 Boost 和 c++11 标准。

using namespace boost::gregorian;
long dateDifference( string start_date, string end_date ) {

            date _start_date(from_simple_string(start_date));
            date _end_date(from_simple_string(end_date));


            long difference = ( _start_date - _end_date ).days();

            return difference;

        }

这只返回两个日期之间的天数，不考虑周末。有人能指出我正确的方向吗？我似乎无法找出解决方案。

谢谢， 最大

Answer 1

没有循环的 O(1) 解决方案:

#include <boost/date_time.hpp>
using namespace std;
using namespace boost::gregorian;

long countWeekDays( string d0str, string d1str ) {
    date d0(from_simple_string(d0str));
    date d1(from_simple_string(d1str));
    long ndays = (d1-d0).days() + 1; // +1 for inclusive
    long nwkends = 2*( (ndays+d0.day_of_week())/7 ); // 2*Saturdays
    if( d0.day_of_week() == boost::date_time::Sunday ) ++nwkends;
    if( d1.day_of_week() == boost::date_time::Saturday ) --nwkends;
    return ndays - nwkends;
}

基本思路是先统计所有星期六，公式(ndays+d0.day_of_week())/7可以方便地给出。将此值加倍即可获得所有星期六和星期日，但开始和结束日期可能落在周末的情况除外，这会通过 2 个简单测试进行调整。

测试它:

#include <iostream>
#include <cassert>
#include <string>

//      January 2014    
//  Su Mo Tu We Th Fr Sa
//            1  2  3  4
//   5  6  7  8  9 10 11
//  12 13 14 15 16 17 18
//  19 20 21 22 23 24 25
//  26 27 28 29 30 31
int main()
{
  assert(countWeekDays("2014-01-01","2014-01-01") == 1);
  assert(countWeekDays("2014-01-01","2014-01-02") == 2);
  assert(countWeekDays("2014-01-01","2014-01-03") == 3);
  assert(countWeekDays("2014-01-01","2014-01-04") == 3);
  assert(countWeekDays("2014-01-01","2014-01-05") == 3);
  assert(countWeekDays("2014-01-01","2014-01-06") == 4);
  assert(countWeekDays("2014-01-01","2014-01-10") == 8);
  assert(countWeekDays("2014-01-01","2014-01-11") == 8);
  assert(countWeekDays("2014-01-01","2014-01-12") == 8);
  assert(countWeekDays("2014-01-01","2014-01-13") == 9);
  assert(countWeekDays("2014-01-02","2014-01-13") == 8);
  assert(countWeekDays("2014-01-03","2014-01-13") == 7);
  assert(countWeekDays("2014-01-04","2014-01-13") == 6);
  assert(countWeekDays("2014-01-05","2014-01-13") == 6);
  assert(countWeekDays("2014-01-06","2014-01-13") == 6);
  assert(countWeekDays("2014-01-07","2014-01-13") == 5);
  cout << "All tests pass." << endl;
  return 0;
}

这适用于 Gregorian calendar 中的任何日期范围，目前支持 1400-10000 年。请注意，不同的国家在不同的时间采用了公历。例如，英国人在 1752 年 9 月从儒略历改为公历，所以他们那个月的日历看起来像这样

   September 1752
Su Mo Tu We Th Fr Sa
       1  2 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30