Leetcode: Binary Search

Binary Search



Similar Problems:


Given a sorted (in ascending order) integer array nums of n elements and a target value, write a function to search target in nums. If target exists, then return its index, otherwise return -1.

Example 1:

Input: nums = [-1,0,3,5,9,12], target = 9
Output: 4
Explanation: 9 exists in nums and its index is 4

Example 2:

Input: nums = [-1,0,3,5,9,12], target = 2
Output: -1
Explanation: 2 does not exist in nums so return -1

Note:

  1. You may assume that all elements in nums are unique.
  2. n will be in the range [1, 10000].
  3. The value of each element in nums will be in the range [-9999, 9999].

Github: code.dennyzhang.com

Credits To: leetcode.com

Leave me comments, if you have better ways to solve.


  • Solution:
// Blog link: https://code.dennyzhang.com/binary-search
// Basic Ideas:
// Complexity: Time O(log(n)), Space O(1)
func search(nums []int, target int) int {
    var m int
    l, r := 0, len(nums)-1
    for l<=r {
        m = l + (r-l)/2
        if nums[m] == target { return m }
        if nums[m] > target {
            r = m-1
        } else {
            l = m+1
        }
    }
    return -1
}
linkedin
github
slack

Share It, If You Like It.

Leave a Reply

Your email address will not be published.