35. Search Insert Position

Easy

Given a sorted array of distinct integers and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.

You must write an algorithm with O(log n) runtime complexity.

Example 1:

Input: nums = [1,3,5,6], target = 5
Output:
 2

Example 2:

Input: nums = [1,3,5,6], target = 2
Output:
 1

Example 3:

Input: nums = [1,3,5,6], target = 7
Output:
 4

Constraints:

• 1 <= nums.length <= 104

• -104 <= nums[i] <= 104

• nums contains distinct values sorted in ascending order.

• -104 <= target <= 104

解題

Runtime: 5 ms, faster than 77.59%

Memory Usage: 2.9 MB, less than 100%

func searchInsert(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--
        } else {
            left++
        }
    }

    if target > nums[left] { return left + 1 }

    return left 
}