Merge Sort Tutorial

Merge sort is a popular sorting algorithm that uses a divide-and-conquer approach. It divides the input array into two halves, sorts them, and then merges them back together. This algorithm has a time complexity of O(n log n) in all cases (worst, average, and best).

Basic Steps

Divide: Split the array into two halves.
Conquer: Recursively sort both halves.
Combine: Merge the two sorted halves into one.

Example

Here's a simple implementation of merge sort in Python:

def merge_sort(arr):
    if len(arr) > 1:
        mid = len(arr) // 2
        L = arr[:mid]
        R = arr[mid:]

        merge_sort(L)
        merge_sort(R)

        i = j = k = 0

        while i < len(L) and j < len(R):
            if L[i] < R[j]:
                arr[k] = L[i]
                i += 1
            else:
                arr[k] = R[j]
                j += 1
            k += 1

        while i < len(L):
            arr[k] = L[i]
            i += 1
            k += 1

        while j < len(R):
            arr[k] = R[j]
            j += 1
            k += 1

# Example usage
arr = [38, 27, 43, 3, 9, 82, 10]
merge_sort(arr)
print(arr)

More Information

For more detailed information on merge sort, you can read our comprehensive guide on Sorting Algorithms.