Friday, 1 December 2017

Explain the algorithm for selection sort.

In selection sort the list is divided into two sub-lists sorted and unsorted. These two lists are divided by imaginary wall. We find a smallest element from unsorted sub-list and swap it to the beginning. And the wall moves one element ahead, as the sorted list is increases and unsorted list is decreases. Assume that we have a list on n elements. By applying selection sort, the first element is compared with all remaining (n-1) elements. The smallest element is placed at the first location. Again, the second element is compared with remaining (n-1) elements. At the time of comparison, the smaller element is swapped with larger element. Similarly, entire array is checked for smallest element and then swapping is done accordingly. Here we need n-1 passes or iterations to completely rearrange the data.

Algorithm for selection sort

selection_sort ( A [ ] , N )
Step 1 : Repeat For K = 0 to N – 2 Begin
Step 2 : Set POS = K
Step 3 : Repeat for J = K + 1 to N – 1 Begin
 If A[ J ] < A [ POS ]
 Set POS = J
 End For
Step 5 : Swap A [ K ] with A [ POS ]
 End For
Step 6 : Exit.

Mukesh Rajput

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Mukesh Rajput