SORTING

  There are a number of sorting techniques that can be employed to sort a given list of data elements.the suitability of a specific techniques in the specific situation depends on a number of factors,such as

1. Size of the data structure. 
2. Algorithm efficiency.
3. Programmer's knowledge of the technique.

 While all the sorting methods produce the same results, that is a list of sorted elements, it is one or more of the above factors that play an important role in choosing a specific sorting technique in a given situation.

Sorting techniques:

• Consider a list L containing 'n' elements,as shown 

                           L1 ,L2,L3........,Ln

• Now there are n! ways in which the elements can be arranged within the list.we can apply a sorting technique to the list L to arrange  the elements in either ascending or descending order.
• If we sort the list in ascending order,then

                  L1<=L2<=L3........<=Ln

• Alternatively,if we arrange the list in descending order,then

                  L1>=L2>=L3........>=Ln

• A telephone directory is one such example where both sorting and searching technique are applied.

EXAMPLE 

   Consider an array A containing 5 elements,as shown below

What would be the resultant array if it is sorted in ascending order & descending order?

Solution:

         (a)Array A sorted in ascending order.
                          

         (b)Array A sorted in descending order.

                          

The number of Sorting methods are given below:

             (1)Insertion sort

           (2)Selection sort

           (3)Shell sort

           (4)Bubble sort

           (5)Quick sort

           (6)Merge sort

           (7)Radix sort

• All sorting techniques which require the data set to be present in the main memory are referred as internal sorting techniques.

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