Searching on Rohit Jha

0x0010 - Searching Algorithms – Part 3

Fri, 18 Nov 2011 18:14:55 +0000

Uniform Binary Search

I came across the uniform binary search algorithm in The Art Of Computer Programming – Volume 3: Sorting and Searching as an optimization of the binary search, invented by the author, Donald Knuth. It works quite well for architectures on which a table lookup is generally faster than an addition and a shift, and also when many searches will be performed on the same array, or on several arrays of the same length.

0x000f - Searching Algorithms – Part 2

Thu, 17 Nov 2011 16:10:43 +0000

Binary Search

The binary search algorithm, a variation of the Dichotomic search, finds the position of a specified “key” within a sorted list/array using the divide and conquer approach.

At each stage, the algorithm compares the input key value with the key value of the middle element of the array. If the keys match, then a matching element has been found so its index, or position, is returned. Otherwise, if the sought key is less than the middle element’s key, then the algorithm repeats its action on the sub-array to the left of the middle element or, if the input key is greater, on the sub-array to the right. If the remaining array to be searched is reduced to zero, then the key cannot be found in the array and a special indication is returned, saying that the key was not found.

0x000e - Searching Algorithms – Part 1

Thu, 10 Nov 2011 08:21:00 +0000

This is the first part of some searching algorithms that I’m implementing. The algorithms are:

Linear Search
Binary Search
Uniform Binary Search
Fibonacci Search
Jump Search
Interpolation Search
Ternary Search

In this part, Linear Search is discussed.

Linear Search

The linear/sequential search technique is the simplest of all searching algorithms and it involves checking every element, one at a time in sequence, until the desired one is found. This type of search is easy to implement, but practical when the list has few elements or the list is unsorted. The best case is when the first element is the one to be found. The worst case is when the element is not found even after searching through the entire list. Thus, both the worst-case and expected cost is asymptotically O(n). Below are some variations of the Linear Search algorithm: