Binary Search¶

You are given an array of distinct integers nums, sorted in ascending order, and an integer target.

Implement a function to search for target within nums. If it exists, then return its index, otherwise, return -1.

Your solution must run in O ( l o g n ) O(logn) time.

Example 1:

Input: nums = [-1,0,2,4,6,8], target = 4

Output: 3 Example 2:

Input: nums = [-1,0,2,4,6,8], target = 3

Output: -1

In [4]:

def binary_search(nums,target):
    l,r=0,len(nums)-1
    while l<=r:
        mid= (l+r)// 2
        if target==nums[mid]:
            return mid
        elif target>nums[mid]:
            l=mid+1
        elif target<nums[mid]:
            r=mid-1

In [5]:

print(binary_search([2,4,8,9,11,15],11))