Binary Search
Description
Given an array of integers nums
which is sorted in ascending order, and an integer target
, write a function to search target
in nums
. If target
exists, then return its index. Otherwise, return -1
.
You must write an algorithm with O(log n)
runtime complexity.
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
Constraints:
1 <= nums.length <= 104
-104 < nums[i], target < 104
- All the integers in
nums
are unique. nums
is sorted in ascending order.
Solution(javascript)
/**
* @param {number[]} nums
* @param {number} target
* @return {number}
*/
var search = function(nums, target) {
for(let i = 0; i < nums.length; i++) {
if (nums[i] == target) {
return i;
}
}
return -1;
};