如何在C/C++中对日期数组进行排序？

给定日期数组, 如何对它们进行排序。

例子：

Input:
       Date arr[] = {{20, 1, 2014}, {25, 3, 2010}, { 3, 12, 1676}, {18, 11, 1982}, {19, 4, 2015}, { 9, 7, 2015}}

Output:
      Date arr[] = {{ 3, 12, 1676}, {18, 11, 1982}, {25, 3, 2010}, {20, 1, 2014}, {19, 4, 2015}, { 9, 7, 2015}}

我们强烈建议你最小化浏览器, 然后先尝试一下

这个想法是使用内置功能

C++中的排序功能

。我们可以编写自己的比较函数, 该函数首先比较年份, 然后比较几个月, 然后比较几天。

下面是一个完整的C++程序。

//C++ program to sort an array of dates
#include<bits/stdc++.h>
using namespace std;
  
//Structure for date
struct Date
{
     int day, month, year;
};
  
//This is the compare function used by the in-built sort
//function to sort the array of dates.
//It takes two Dates as parameters (const is
//given to tell the compiler that the value won't be
//changed during the compare - this is for optimization..)
  
//Returns true if dates have to be swapped and returns
//false if not. Since we want ascending order, we return
//true if the first Date is less than the second date
bool compare( const Date &d1, const Date &d2)
{
     //All cases when true should be returned
     if (d1.year <d2.year)
         return true ;
     if (d1.year == d2.year && d1.month <d2.month)
         return true ;
     if (d1.year == d2.year && d1.month == d2.month &&
                               d1.day <d2.day)
         return true ;
  
     //If none of the above cases satisfy, return false
     return false ;
}
  
//Function to sort array arr[0..n-1] of dates
void sortDates(Date arr[], int n)
{
     //Calling in-built sort function.
     //First parameter array beginning, //Second parameter - array ending, //Third is the custom compare function
     sort(arr, arr+n, compare);
}
  
//Driver Program
int main()
{
     Date arr[] = {{20, 1, 2014}, {25, 3, 2010}, { 3, 12, 1676}, {18, 11, 1982}, {19, 4, 2015}, { 9, 7, 2015}};
     int n = sizeof (arr)/sizeof (arr[0]);
  
     sortDates(arr, n);
  
     cout <<"Sorted dates are\n" ;
     for ( int i=0; i<n; i++)
     {
         cout <<arr[i].day <<" " <<arr[i].month
              <<" " <<arr[i].year;
         cout <<endl;
     }
}

输出如下：

Sorted dates are
3 12 1676
18 11 1982
25 3 2010
20 1 2014
19 4 2015
9 7 2015

同样在C语言中, 我们可以使用qsort()函数。

相关问题：

如何有效地对20年代的大列表日期进行排序

本文作者：Dinesh T.P.D。如果发现任何不正确的地方, 或者想分享有关上述主题的更多信息, 请发表评论。