Golang: Find closest element in array

find_closest.go

func findClosest(arr []int, target int) int {
	n := len(arr)
	if n == 0 {
		panic("empty array")
	}

	if target < arr[0] {
		return arr[0]
	}

	if target > arr[n-1] {
		return arr[n-1]
	}

	left, mid, right := 0, 0, n
	for left < right {
		mid = (left + right) / 2

		if arr[mid] == target {
			return arr[mid]
		}

		if target < arr[mid] {
			if mid > 0 && target > arr[mid-1] {
				return getClosest(arr[mid-1], arr[mid], target)
			}

			right = mid
		} else {
			if mid < n-1 && target < arr[mid+1] {
				return getClosest(arr[mid], arr[mid+1], target)
			}

			left = mid + 1
		}
	}

	return arr[mid]
}

func getClosest(left, right, target int) int {
	if target-left >= right-target {
		return right
	}

	return left
}