What Data Structure Does Merge Sort Use?
Merge Sort is a sorting algorithm that follows the divide and conquer approach. It divides the input array into two halves, sorts them separately, and then merges the sorted halves to produce a sorted output.
Divide and Conquer
In the divide and conquer approach, a problem is divided into smaller subproblems until they become simple enough to solve directly. Once solved, the solutions of the subproblems are combined to solve the original problem.
Merge Sort Process
Merge Sort starts by dividing the input array into two equal halves. This process continues recursively until we reach arrays of size 1 or 0 – which are already sorted by definition.
Once we have divided the array into its smallest components, we start merging them back together in a sorted manner. This merging process combines pairs of adjacent arrays and creates larger sorted arrays.
The Merge Step
The merge step is where Merge Sort utilizes a data structure called a temporary array. This temporary array is used to store the merged result of two smaller sorted arrays.
To merge two sorted arrays, we compare elements from both arrays one by one and place them in their correct order in the temporary array. The process continues until all elements from both arrays are merged into the temporary array.
Benefits of Using a Temporary Array
The use of a temporary array in Merge Sort provides several benefits:
- Efficiency: With a temporary array, we can efficiently merge two sorted arrays without overwriting any elements or losing any data.
- In-place Sorting: Merge Sort can be adapted for an in-place sorting algorithm, meaning it doesn’t require additional memory space apart from the input array and the temporary array.
- Stability: Merge Sort is a stable sorting algorithm, preserving the relative order of equal elements. The temporary array helps maintain this stability during the merging process.
In conclusion, Merge Sort uses a temporary array to efficiently merge two sorted arrays during the merging step of its divide and conquer approach. This data structure allows for an efficient, in-place, and stable sorting algorithm.