Example: Simple Insertion Sort using Array in C++

// Simple Insertion Sort using Array
#include <iostream> // For input/output operations

// Function to perform insertion sort on an array
// arr[]: The array to be sorted
// n: The size of the array
void insertionSort(int arr[], int n) {
    // Loop through the array starting from the second element (index 1)
    // because the first element (index 0) is considered sorted by itself.
    for (int i = 1; i < n; i++) {
        int key = arr[i]; // Store the current element as 'key' to be inserted
        int j = i - 1;    // Initialize 'j' to the last element of the sorted subarray (to the left of key)

        // Move elements of arr[0...i-1], that are greater than key,
        // to one position ahead of their current position.
        // This creates space for the 'key'.
        while (j >= 0 && arr[j] > key) {
            arr[j + 1] = arr[j]; // Shift element arr[j] to the right
            j = j - 1;           // Move 'j' to the previous element in the sorted part
        }
        arr[j + 1] = key; // Place the 'key' in its correct sorted position
    }
}

// Function to print the elements of an array
void printArray(int arr[], int n) {
    for (int i = 0; i < n; i++) {
        std::cout << arr[i] << " ";
    }
    std::cout << std::endl;
}

int main() {
    // Step 1: Declare and initialize an array
    int arr[] = {12, 11, 13, 5, 6};
    // Calculate the size of the array
    int n = sizeof(arr) / sizeof(arr[0]);

    // Step 2: Print the original array to show its initial state
    std::cout << "Original array: ";
    printArray(arr, n);

    // Step 3: Call the insertionSort function to sort the array in ascending order
    insertionSort(arr, n);

    // Step 4: Print the sorted array to show the result
    std::cout << "Sorted array (ascending): ";
    printArray(arr, n);

    return 0;
}