## Leetcode

Given a sorted array of integers, find the starting and ending position of a given target value.

Your algorithm's runtime complexity must be in the order of

*O*(log*n*).
If the target is not found in the array, return

`[-1, -1]`

.
For example,

Given

return

Given

`[5, 7, 7, 8, 8, 10]`

and target value 8,return

`[3, 4]`

.
Solution: because of O(logn), so we should consider about binary search, so how to apply binary search to find the low bound and high bound? We can make target -0.5 for searching low bound and target+0. 5 for the high bound. Be careful the corner case