Ex6

def find_peak(elements):
    if len(elements) < 0:
        return None

    if len(elements) == 1:
        return elements[0]

    if len(elements) == 2:
        if elements[0] > elements[1]:
            return elements[0]
        else:
            return elements[1]

    mid = len(elements) / 2

    if elements[mid] > elements[mid - 1] and\
            elements[mid] > elements[mid + 1]:
        return elements[mid]

    elif elements[mid] > elements[mid - 1] and\
            elements[mid] < elements[mid + 1]:
        return find_peak(elements[mid:])

    elif elements[mid] < elements[mid - 1] and\
            elements[mid] > elements[mid + 1]:
        return find_peak(elements[:mid])

if __name__ == '__main__':
    X = [1, 3, 50, 51, 10, 9, 7, 6]

    print find_peak(X)