public class BinarySearch {

    public static void main (String[] argv)
    {
        // Sorted array:
        int[] testData = {24, 32, 41, 42, 51, 63, 71, 73, 85, 87};

        // Create a test value to search for.
        int searchTerm = 32;
        
        // Note: initially, the "range" is 0,...,testData.length-1
        boolean found = binarySearch (testData, searchTerm, 0, testData.length-1);

        // Print result.
        System.out.println ("found = " + found);

        // Another search.
        searchTerm = 55;
        found = binarySearch (testData, searchTerm, 0, testData.length-1);
        System.out.println ("found = " + found);
    }


    static boolean binarySearch (int[] A, int value, int start, int end)
    {
        // Bottom-out cases:
        if (start == end) {
            // There's only one value to check: A[start]=value?
            if (A[start] == value) {
                return true;
            }
            else {
                return false;
            }
        }
        
        // If there are only two values in the range:
        if (end == start+1) {
            if (A[start] == value) {
                return true;
            }
            else if (A[end] == value) {
                return true;
            }
            else {
                return false;
            }
        }

        // Otherwise recurse. We know that A[start] <= value <= A[end].

        // Find the middle:
        int mid = (start + end) / 2;

        if (value <= A[mid]) {
            // Search the left half: A[start],...,A[mid]
            return binarySearch (A, value, start, mid);
        }
        else {
            // Search the right half: A[mid+1],...,A[end]
            return binarySearch (A, value, mid+1, end);
        }
    }

}