What do you mean by searching technique?

Answer 1

"Searching technique" defines the way in which we look for a given value within a set of values. We define these techniques using algorithms.

Searching is always quicker when the data is in sorted order. We start in the middle of the set. If that's our value, we're done. Otherwise, we compare the middle value with the value we seek to determine which side of the set contains our value. We then discard the other half and repeat the process with the remaining half. If the remaining half is empty, the value does not exist.

This technique is known as a binary search and can be performed efficiently on any container that permits constant-time random-access, such as an array. Balanced binary trees can also be used. Lists do not support constant-time random-access so the benefit of binary search is often outweighed by added complexity of identifying the middle element of a range.

If the data is unsorted, we must use a linear search. Typically we start at the first element and work our way through to the last element, stopping when we find the value or reach the end of the sequence. Linear search can be performed on any container that allows forward traversal, including arrays and lists.

The return value of a search algorithm is typically an iterator; a pointer to the element or node that holds the value. If the value does not exist, we typically return an iterator to the one-past-the-end of the sequence. In the case of arrays we could return the zero-based index of the value, returning the count of elements when the value does not exist, however it is better to use iterators as this allows us to generalise our algorithms to cater for all container types.