Sorting in Cilk

In Cilk, we can use the C++ Standard Library for sorting operations. The <algorithm> header provides sorting functionality for various container types.

#include <cilk/cilk.h>
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>

int main() {
    // Sorting functions work for any comparable type.
    // For strings, we can use std::vector<string>.
    std::vector<std::string> strs = {"c", "a", "b"};
    std::sort(strs.begin(), strs.end());
    std::cout << "Strings: ";
    for (const auto& s : strs) {
        std::cout << s << " ";
    }
    std::cout << std::endl;

    // An example of sorting integers.
    std::vector<int> ints = {7, 2, 4};
    std::sort(ints.begin(), ints.end());
    std::cout << "Ints:    ";
    for (const auto& i : ints) {
        std::cout << i << " ";
    }
    std::cout << std::endl;

    // We can also use the algorithm library to check if
    // a vector is already in sorted order.
    bool s = std::is_sorted(ints.begin(), ints.end());
    std::cout << "Sorted:  " << (s ? "true" : "false") << std::endl;

    return 0;
}

This Cilk program demonstrates sorting functionality similar to the original example. Here’s a breakdown of the changes:

1. We include necessary headers: <cilk/cilk.h> for Cilk support, <iostream> for input/output, <vector> for dynamic arrays, <string> for string operations, and <algorithm> for sorting functions.

2. Instead of slices, we use std::vector which is a dynamic array in C++.

3. The sort function from the <algorithm> library is used to sort the vectors. It takes iterators to the beginning and end of the range to be sorted.

4. To print the sorted vectors, we use range-based for loops, which provide a more convenient way to iterate over containers in C++.

5. The is_sorted function from the <algorithm> library is used to check if a vector is sorted, similar to the slices.IsSorted function in the original example.

To compile and run this Cilk program:

$ cilk++ -std=c++11 sorting.cpp -o sorting
$ ./sorting
Strings: a b c 
Ints:    2 4 7 
Sorted:  true

Note that Cilk extends C++, so we can use C++ standard library functions and containers. The Cilk runtime will automatically parallelize certain operations when possible, potentially providing performance benefits for larger datasets.