Example: Insertion Sort using Function in C

// Insertion Sort using Function
#include <stdio.h> // Required for input/output operations

// Function to print an array
void printArray(int arr[], int size) {
    // Step 1: Iterate through the array from the first element to the last
    for (int i = 0; i < size; i++) {
        // Step 2: Print each element followed by a space
        printf("%d ", arr[i]);
    }
    // Step 3: Print a newline character to move to the next line
    printf("\n");
}

// Function to perform insertion sort on an array
void insertionSort(int arr[], int size) {
    // Step 1: Outer loop to iterate from the second element to the last element
    // The first element (index 0) is considered already sorted
    for (int i = 1; i < size; i++) {
        // Step 2: Store the current element to be inserted in its correct position
        int key = arr[i];
        // Step 3: Initialize 'j' to the index of the element just before 'key'
        int j = i - 1;

        // Step 4: Inner loop to shift 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' (current element) in its correct sorted position
        arr[j + 1] = key;
    }
}

int main() {
    // Step 1: Declare and initialize an unsorted integer array
    int arr[] = {12, 11, 13, 5, 6};
    // Step 2: Calculate the size of the array
    int size = sizeof(arr) / sizeof(arr[0]);

    // Step 3: Print the original array
    printf("Original array: ");
    printArray(arr, size);

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

    // Step 5: Print the sorted array
    printf("Sorted array: ");
    printArray(arr, size);

    return 0; // Indicate successful execution
}