# Write an algorithm for binary search with example

So consider an array with 8 elements, after the first unsuccessful, binary sort will cut down the list to half, leaving behind 4 elements, then 2 elements after the second unsuccessful guess, and finally only 1 element will be left, which will either be the target or not, checking that will involve one more step.

Binary Search Algorithm Binary search algorithm finds a given element in a list of elements with O log n time complexity where n is total number of elements in the list. This time it is 5. Step 1 - Read the search element from the user. We find that the value at location 4 is 27, which is not a match. If the middle item is greater than the item, then the item is searched in the sub-array to the left of the middle item. Time Complexity of Binary Search O log n When we say the time complexity is log n, we actually mean log2 n, although the base of the log doesn't matter in asymptotic notations, but still to understand this better, we generally consider a base of 2.

The following steps will be followed to find the number 4 with binary search in a sequential array of these numbers. The binary search can not be used for a list of elements arranged in random order. With binary search algorithm, it is possible to find the searched value to log2N comparisons in an N-element array.

Otherwise narrow it to the upper half. Rated 7/10 based on 85 review