inplacemergesort

Cheejyg/Integration-of-Mergesort-and-Insertion-Sort

As a divide-and-conquer algorithm, Mergesort breaks the input array into subarrays and recursively sort them. When the sizes of sub-arrays are small, the overhead of many recursive calls makes the algorithm inefficient. This problem can be remedied by choosing a small value of S as a threshold for the size of sub-arrays. When the size of a sub-array in a recursive call is less than or equal to the value of S, the algorithm will switch to Insertion sort, which is efficient for small input. A pseudocode of the modified Mergesort is given below: