Data structure  Explain quick sort and merge sort
algorithms.  Feb 27, 2010, 11:15 am by Rajmeet Ghai
Explain quick sort and merge sort algorithms.
Quick sort – Divides the array elements in two halves or
partitions. On dividing, the quick sort procedure is recursively called to sort
the two halves. A “pivot” is used as the center point and elements less than
the pivot are moved to the left or before the pivot and elements greater than
pivot are moved to the right.
Merge sort Merge sort is based on divide and conquer
mechanism. The array elements are divided into partitions (n/2). Each partition
is sorted recursively and then merged.
Data structure  Explain quick sort and merge sort
algorithms.  July 31, 2009, 10:55 am by Vidya Sagar
Explain quick sort and merge sort algorithms.
Quick sort employs the ‘divide and conquer’ concept by dividing the list of
elements into two sub elements
The process is as follows:
1. Select an element, pivot, from the list.
2. Rearrange the elements in the list, so that all elements those are less than
the pivot are arranged before the pivot and all elements those are greater than
the pivot are arranged after the pivot. Now the pivot is in its position.
3. Sort the both sub lists – sub list of the elements which are less than the
pivot and the list of elements which are more than the pivot recursively.
Merge Sort: A comparison based sorting algorithm. The input
order is preserved in the sorted output.
Merge Sort algorithm is as follows:
1. The length of the list is 0 or 1, and then it is considered as sorted.
2. Other wise, divide the unsorted list into 2 lists each about half the size.
3. Sort each sub list recursively. Implement the step 2 until the two sub lists
are sorted.
4. As a final step, combine (merge) both the lists back into one sorted
list.
Data structure  What is merge sort algorithm?  August
02, 2008 at 10:40 AM by Amit Satpute
What is merge sort algorithm?
Answer
A merge sort algorithm that splits the items to be sorted into two groups,
recursively sorts each group, and merges them into a final, sorted sequence.
Run time is T(n log n).
If n<2 then the array is already sorted. Stop now.
Otherwise, n>1, and we perform the following three steps in sequence:
Sort the left half of the the array.
Sort the right half of the the array.
Merge the nowsorted left and right halves.
