CODEWITHSUNDEEP
c++sortingvector
Oscar
Oscar

Reputation: 243

C++ vector of class custom sort

I have C++ code. There is a vector of class. I need to sort this vector in a bit custom way.

Here is my class:

class Sales
{
   public:
      string customer_name;
      string category;
      string aircraft;
      string day;
      string time;
      int week;
      int ticket_price;
      string payment;

   public:
      Sales () { 
         customer_name = "";
         category = "";
         aircraft = "";
         day = "";
         time = "";
         week = 0;
         ticket_price = 0;
         payment = "";
      }

      Sales (string f_cat, string airc, string xday, string xtime, int xweek) {
         customer_name = "";
         category = f_cat;
         aircraft = airc;
         day = xday;
         time = xtime;
         week = xweek;
         ticket_price = 0;
         payment = "";
      }  
};

Lets say we have:

vector <Sales> list;

Imagine that list has got populated record And I want to get this sorted like below logic:

sort_string = day + time + week + category + aircraft;

Example records:

Sunday, 12:00, 1, Comm, b777
Monday, 10:00, 1, Comm, b777
Monday, 10:00, 1, Comm, a321
Monday, 12:00, 1, Comm, a321
Friday, 09:00, 1, Comm, a321

Expected Sort:

Monday, 10:00, 1, Comm, a321
Monday, 10:00, 1, Comm, b777
Monday, 12:00, 1, Comm, a321
Friday, 09:00, 1, Comm, a321
Sunday, 12:00, 1, Comm, b777

Is this possible? if Yes, then how?

Thanks.

Upvotes: 3

Views: 287

Answers (2)

Boris Ivanov
Boris Ivanov

Reputation: 4254

if you will implement boolean function as member it must be const type

    bool operator<( const Sales& rhs) const{ 
        if (customer_name < rhs.customer_name ) return true; 
        if (category < rhs.category ) return true; 
        return false;
    }

See working example

Upvotes: 0

Kiril Kirov
Kiril Kirov

Reputation: 38173

Yes, it is.

Define 

bool Sales::operator<( const Sales& other ) // member

or 

bool operator<( const Sales& lhs, const Sales& rhs) // global

and use std::sort.

Example with only two int variables, as they are the easiest ones:

bool operator<( const Sales& lhs, const Sales& rhs)
{
    if( lhs.week < rhs.week ) 
         return true;
    else if( lhs.week > rhs.week )  
         return false;

    if( lhs.price < rhs.price ) 
         return true;
    else if( lhs.price > rhs.price )  
         return false;

    // ...

    return false;
}

Of course, your definition will be more complicated, because the other fields are more complicated for comparing (the weekday for example), but I hope you get the point.

Then:

#include <algorithm>
// ...
std::sort( list.begin(), list.end() );

By the way, list is bad name for variable, as it may conflict with std::list in some cases.

Upvotes: 7

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