Binary Search

Binary search (a.k.a Half-Interval Search) algorithms finds the position of a target value within an array.

• C#
• VB.Net
• C
• C++
• PHP

									Public Shared Function BinarySearch(data As Integer(), value As Integer) As Integer
	Dim low As Integer = 0, high As Integer = data.Length - 1, midpoint As Integer = 0

	While low <= high
		midpoint = low + (high - low) \ 2

		If value = data(midpoint) Then
			Return midpoint
		ElseIf value < data(midpoint) Then
			high = midpoint - 1
		Else
			low = midpoint + 1
		End If
	End While

	Return -1
End Function
								

Example

									Dim data As Integer() = New Integer(9) {}
For i As Integer = 0 To 9
    data(i) = i * 10
Next

Dim value = BinarySearch(data, 60)
								

Output

									6