Difference between revisions of "cpp/algorithm/stable sort"

Revision as of 02:00, 21 November 2018

Sorts the elements in the range [first, last) in ascending order. The order of equivalent elements is guaranteed to be preserved.

Parameters

Return value

(none)

Complexity

O(N·log(N)²), where N = std::distance(first, last) applications of cmp. If additional memory is available, then the complexity is O(N·log(N)).

Exceptions

The overloads with a template parameter named ExecutionPolicy report errors as follows:

• If execution of a function invoked as part of the algorithm throws an exception and ExecutionPolicy is one of the standard policies, std::terminate is called. For any other ExecutionPolicy, the behavior is implementation-defined.
• If the algorithm fails to allocate memory, std::bad_alloc is thrown.

Notes

This function attempts to allocate a temporary buffer equal in size to the sequence to be sorted. If the allocation fails, the less efficient algorithm is chosen.

Example

#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
 
struct Employee
{
    int age;
    std::string name;  // Does not participate in comparisons
};
 
bool operator<(const Employee & lhs, const Employee & rhs)
{
    return lhs.age < rhs.age;
}
 
int main()
{
    std::vector<Employee> v =
    { 
        {108, "Zaphod"},
        {32, "Arthur"},
        {108, "Ford"},
    };  
 
    std::stable_sort(v.begin(), v.end());
 
    for (const Employee & e : v)
        std::cout << e.age << ", " << e.name << '\n';
}

32, Arthur
108, Zaphod
108, Ford

See also