What is a Merge sort algorithm?

On average merge sort is more efficient however insertion sort could potentially be faster. As a result it depends how close to reverse order the data is. If it is likely to be mostly sorted,...

nlog2n

quicksort should be O(n^2), but merge sort should be O(nlogn).but if you can modify partition algorithm with checking all values same in array from p to r, it could be O(nlogn).

quick sort is better,bcoz it doesn't take extra space of memory...

Merge sort is good for large data sets, while insertion sort is good for small data sets.