Example: Insertion Sort using Function in C++

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

// Function to perform Insertion Sort on an array
void insertionSort(int arr[], int n) {
    // Step 1: Iterate from the second element (index 1) to the end of the array
    for (int i = 1; i < n; i++) {
        // Step 2: Store the current element to be inserted
        int key = arr[i];
        // Step 3: Initialize j to the element just before the key
        int j = i - 1;

        // Step 4: Move elements of arr[0...i-1], that are greater than key,
        //         to one position ahead of their current position
        while (j >= 0 && arr[j] > key) {
            arr[j + 1] = arr[j]; // Shift element to the right
            j = j - 1;           // Move to the left to compare with the next element
        }
        // Step 5: Place the key at its correct position in the sorted subarray
        arr[j + 1] = key;
    }
}

// Function to print 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 an unsorted integer array
    int arr[] = {12, 11, 13, 5, 6};
    // Step 2: Calculate the size of the array
    int n = sizeof(arr) / sizeof(arr[0]);

    // Step 3: Print the original array
    std::cout << "Original array: ";
    printArray(arr, n);

    // Step 4: Call the insertionSort function to sort the array
    insertionSort(arr, n);

    // Step 5: Print the sorted array
    std::cout << "Sorted array: ";
    printArray(arr, n);

    return 0;
}