704. Binary Search
Easy
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
numsare unique. numsis sorted in ascending order.
Binary search
func search(nums []int, target int) int {
left := 0
right := len(nums)-1
for left <= right {
mid := ( left + right )/2
if nums[mid] == target { return mid }
if nums[mid] > target {
right = mid - 1
} else {
left = mid + 1
}
}
return -1
}