Search for a Range

Given a sorted array of integers A(0 based index) of size N, find the starting and the ending position of a given integer B in array A.

Your algorithm's runtime complexity must be in the order of O(log n).

Return an array of size 2, such that the first element = starting position of B in A and the second element = ending position of B in A, if B is not found in A return [-1, -1].

1 <= N <= 10⁶

1 <= A[i], B <= 10⁹

The first argument given is the integer array A.
The second argument given is the integer B.

Return an array of size 2, such that the first element = starting position of B in A and the second element = the ending position of B in A if B is not found in A return [-1, -1].

Input 1:

 A = [5, 7, 7, 8, 8, 10]
 B = 8

Input 2:

 A = [5, 17, 100, 111]
 B = 3

Output 1:

 [3, 4]

Output 2:

 [-1, -1]

Explanation 1:

 The first occurence of 8 in A is at index 3.
 The second occurence of 8 in A is at index 4.
 ans = [3, 4]

Explanation 2:

 There is no occurence of 3 in the array.