Sorting algorithm is an algorithm that puts elements of a list in a certain order . The most-used orders are numerical order and lexicographical order.
Sorting algorithm classification:
Stability-Maintaining relative order of records with equal keys.
Methods applied like insertion,exchange,,selection,merging etc.
Sorting is a process of linear ordering of list of objects
Sorting techniques are categoried into:
1. Internal sorting
2. External sorting
It takes the place in the main memory of a computer.
Eg: Bubble sort,Insertion sort,Shell sort,Quick sort,Heap Sort,etc
It takes the place in secondary memory of a computer,Since the number of objects to be stored is too large to fit in main memory
Eg:Merge sort,Multiway Merge,Polyphase merge.
Insertion sort is a simple sorting algorithm, a comparison sort in which the sorted array (or list) is built one entry at a time. It is much less efficient on large lists than more advanced algorithms such as quicksort , heapsort, or merge sort.
Insertion sorts works by taking elements from the list one by one and inserting them in their current position into a new sorted list.
Insertion sort consists of N-1 passes.
Insertion Sort Provides Several Advantages:
- Simple implementation
- Efficient for (quite) small data sets
- Adaptive, i.e. efficient for data sets that are already substantially sorted: the time complexity is O( n + d), where d is the number of inversions
- More efficient in practice than most other simple quadratic (i.e. O ( n 2)) algorithms such as selection sort or bubble sort: the average running time is n 2/4, and the running time is linear in the best case
- Stable, i.e. does not change the relative order of elements with equal keys
- In-place , i.e. only requires a constant amount O(1) of additional memory space
- Online , i.e. can sort a list as it receives it
Limitations of insertion sort:
It is relatively efficient for small lists and mostly- sorted list.
It is expensive because of shifting all following elements by one.
Analysis of insertion sort:
Worest case performance O(n2)
Best case performance O(n)
Average case performance O(n2)
Step 1: Read the input list size.
iv) list [swap+1]
Step 2: Read the list elements.
step 3: pass=1
step 4: Repeat the following steps until pass reach size-1 (for N-1 passes)
iii) Repeat the follwoing steps if this condition is true list[swap]>key and swap >= 0.(for comparision).
a) list [sawp+1]=list[swap ]
C Program To Implement Insertion Sort
CPP Program To Insertion Sort