Given an input a[]={5,3,2,1,0}, key=1, what is position of key element ( assume binary search)102Error

Binary search is a fast search algorithm with run-time complexity of Ο(log n). This search algorithm works on the principle of divide and conquer. However, for Binary Search to work, the array must be sorted.

The given array is a[]={5,3,2,1,0}, which is not sorted. Therefore, we cannot use binary search on this array.

If we sort the array in ascending order, we get a[]={0,1,2,3,5}. Now, we can apply binary search to find the key=1.

Here are the steps for binary search:

1. Find the middle element of the array. In this case, the middle element is 2 (at index 2).

2. Since the key=1 is less than the middle element, we ignore the right half of the array and consider the left half for the next step. Now, our array becomes a[]={0,1}.

3. Again, find the middle element of the array. In this case, the middle element is 0 (at index 0).

4. Since the key=1 is greater than the middle element, we ignore the left half of the array and consider the right half for the next step. Now, our array becomes a[]={1}.

5. The middle (and only) element of this array is 1, which is equal to the key. Therefore, we have found the key at index 1 (in the sorted array).

So, the position of the key element (1) in the sorted array is 1. However, in the original unsorted array a[]={5,3,2,1,0}, the position of the key element (1) is 3.