Here we will see what are the differences between qsort() in C, and sort() in C++.
The C provides qsort() function, that can be used for sorting an array. The function arguments and syntax is like below.
void qsort(void *base, size_t num, size_t size, int (*comparator) (const void*, const void*));
This function takes the base address of that array, the number of elements of that array. Size of each item in the array, and a comparator function.
The C++ provides sort() function. This is present inside C++ STL. The arguments and syntax is like below.
void sort(T first, T last, Compare c);
Here the order of repeated elements is not guaranteed to be preserved. For that purpose, we can use the stable_sort provided by the C++ STL.
The differences between qsort() and sort()
| qsort() in C | sort() in C++ |
|---|---|
| It uses quicksort algorithm. | It uses introsort. This is hybrid sorting algorithm. Here different implementations use different algorithm. The GNU C++ STL uses three-part hybrid sorting. Introsort, Quicksort and Insertion Sort. |
| The C standard does not talk about the complexities of this sorting algorithm. | In this case the complexity is O(n logn) in worst case in C++11 sort(). Some previous version sort() takes O(n2) in worst case, and in average case, they took O(nlogn). |
| Running time of this sort is larger than sort() | The running time is lesser than qsort(). |
| qsort() is not flexible for different kinds of data. | sort() is flexible. This can sort C arrays, C++ vectors, C++ deques, and some other containers also. |
| This sort is not more type safed. It uses unsafe void pointers to access the data. | This sorting technique is more safe. It does not require any unsafe void pointer for accessing the data. |