Sort array using inbuilt sort function in decreasing order

To sort an array in C++ in decreasing order using the inbuilt sort function, you need to follow these steps:

  1. Include the necessary header file: Begin by including the <algorithm> header file, which contains the sort function.

  2. Create an array: Declare and initialize an array with the elements you want to sort.

  3. Specify the range: Pass the starting and ending iterators of the array to the sort function. This specifies the range of elements to be sorted.

  4. Specify the comparison function: By default, the sort function sorts the elements in ascending order. To sort in descending order, you need to specify a comparison function that compares the elements in reverse order.

  5. Define the comparison function: Create a comparison function that takes two elements as parameters and returns true if the first element should appear before the second element in the sorted order. Otherwise, it should return false. In this case, the function should return true if the first element is greater than the second element.

  6. Call the sort function: Finally, call the sort function with the specified range and comparison function.

Here is an example code snippet that demonstrates sorting an array in decreasing order using the sort function:

#include <algorithm>
#include <iostream>

bool compare(int a, int b) {
    return a > b;
}

int main() {
    int arr[] = {5, 2, 8, 1, 9};
    int n = sizeof(arr) / sizeof(arr[0]);

    std::sort(arr, arr + n, compare);

    std::cout << "Sorted array in decreasing order: ";
    for (int i = 0; i < n; i++) {
        std::cout << arr[i] << " ";
    }

    return 0;
}

In this example, the array {5, 2, 8, 1, 9} is sorted in decreasing order using the sort function and the compare function. The output will be Sorted array in decreasing order: 9 8 5 2 1.