Function BinaryIterative

search/binary.go:23–38

BinaryIterative search for target within a sorted array by repeatedly dividing the array in half and comparing the midpoint with the target. Unlike Binary, this function uses iterative method and not recursive. If a target is found, the index of the target is returned. Else the function return -1 an

(array []int, target int)

// Unlike Binary, this function uses iterative method and not recursive.
// If a target is found, the index of the target is returned. Else the function return -1 and ErrNotFound.
func BinaryIterative(array []int, target int) (int, error) {
	startIndex := 0
	endIndex := len(array) - 1
	var mid int
	for startIndex <= endIndex {
		mid = int(startIndex + (endIndex-startIndex)/2)
		if array[mid] > target {
			endIndex = mid - 1
		} else if array[mid] < target {
			startIndex = mid + 1
		} else {
			return mid, nil
		}
	}
	return -1, ErrNotFound
}

// LowerBound returns index to the first element in the range [0, len(array)-1] that is not less than (i.e. greater or equal to) target.
// return -1 and ErrNotFound if no such element is found.