std::sort() en C++ STL

Hemos discutido qsort() en C. C++ STL proporciona una función de clasificación similar que clasifica un vector o una array (elementos con acceso aleatorio)

Por lo general, toma dos parámetros, el primero es el punto de la array/vector desde donde debe comenzar la clasificación y el segundo parámetro es la longitud hasta la que queremos que se clasifique la array/vector. El tercer parámetro es opcional y se puede utilizar en casos como si queremos ordenar los elementos lexicográficamente.

// C++ program to demonstrate default behaviour of
// sort() in STL.
#include <bits/stdc++.h>
using namespace std;
  
int main()
{
    int arr[] = { 1, 5, 8, 9, 6, 7, 3, 4, 2, 0 };
    int n = sizeof(arr) / sizeof(arr[0]);
  
    /*Here we take two parameters, the beginning of the
    array and the length n upto which we want the array to
    be sorted*/
    sort(arr, arr + n);
  
    cout << "\nArray after sorting using "
            "default sort is : \n";
    for (int i = 0; i < n; ++i)
        cout << arr[i] << " ";
  
    return 0;
}

// C++ program to demonstrate descending order sort using
// greater<>().
#include <bits/stdc++.h>
using namespace std;
  
int main()
{
    int arr[] = { 1, 5, 8, 9, 6, 7, 3, 4, 2, 0 };
    int n = sizeof(arr) / sizeof(arr[0]);
  
    sort(arr, arr + n, greater<int>());
  
    cout << "Array after sorting : \n";
    for (int i = 0; i < n; ++i)
        cout << arr[i] << " ";
  
    return 0;
}

// C++ program to demonstrate sort()
  
#include <bits/stdc++.h>
using namespace std;
  
int main()
{
    int arr[] = { 0, 1, 5, 8, 9, 6, 7, 3, 4, 2 };
    int n = sizeof(arr) / sizeof(arr[0]);
  
    // Sort the elements which lies in the range of 2 to
    // (n-1)
    sort(arr + 2, arr + n);
  
    cout << "Array after sorting : \n";
    for (int i = 0; i < n; ++i)
        cout << arr[i] << " ";
  
    return 0;
}
// This code is contributed by Suruchi Kumari

// A C++ program to demonstrate
// STL sort() using
// our own comparator
#include <bits/stdc++.h>
using namespace std;
  
// An interval has a start
// time and end time
struct Interval {
    int start, end;
};
  
// Compares two intervals
// according to starting times.
bool compareInterval(Interval i1, Interval i2)
{
    return (i1.start < i2.start);
}
  
int main()
{
    Interval arr[]
        = { { 6, 8 }, { 1, 9 }, { 2, 4 }, { 4, 7 } };
    int n = sizeof(arr) / sizeof(arr[0]);
  
    // sort the intervals in increasing order of
    // start time
    sort(arr, arr + n, compareInterval);
  
    cout << "Intervals sorted by start time : \n";
    for (int i = 0; i < n; i++)
        cout << "[" << arr[i].start << "," << arr[i].end
             << "] ";
  
    return 0;
}

#include <algorithm>
#include <iostream>
using namespace std;
  
template <class T>
class Comparator { // we pass an object of this class as
                   // third arg to sort function...
public:
    bool operator()(T x1, T x2)
    {
        return x1 < x2;
    }
};
  
template <class T> bool funComparator(T x1, T x2)
{ // return type is bool
    return x1 <= x2;
}
  
void show(int a[], int array_size)
{
    for (int i = 0; i < array_size; i++) {
        cout << a[i] << " ";
    }
}
  
int main()
{
    int a[] = { 1, 5, 8, 9, 6, 7, 3, 4, 2, 0 };
    int asize = sizeof(a) / sizeof(int);
    cout << "The array before sorting is : ";
    show(a, asize);
    cout << endl << "The array after sorting is(asc) :";
    sort(a, a + asize);
    show(a, asize);
    cout << endl << "The array after sorting is(desc) :";
    sort(a, a + asize, greater<int>());
    show(a, asize);
    cout << endl
         << "The array after sorting is(asc but our "
            "comparator class) :";
    sort(a, a + asize, Comparator<int>());
    show(a, asize);
    cout << endl
         << "The array after sorting is(asc but our "
            "comparator function) :";
    sort(a, a + asize, funComparator<int>);
    show(a, asize);
  
    return 0;
}