Example: Simple Insertion Sort in C

// Simple Insertion Sort
#include <stdio.h>

// Function to print an array
void printArray(int arr[], int size) {
    for (int i = 0; i < size; i++) {
        printf("%d ", arr[i]);
    }
    printf("\n");
}

// Function to perform insertion sort
void insertionSort(int arr[], int n) {
    int i, key, j;
    for (i = 1; i < n; i++) {
        key = arr[i]; // Store the current element to be inserted
        j = i - 1;   // Start comparing with the element just before 'key'

        // 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 next element
        }
        arr[j + 1] = key; // Place key in its correct position
    }
}

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

    // Step 2: Print the original array
    printf("Original array: ");
    printArray(arr, n);

    // Step 3: Perform insertion sort
    insertionSort(arr, n);

    // Step 4: Print the sorted array
    printf("Sorted array (ascending): ");
    printArray(arr, n);

    return 0;
}