def linear_search(theList, x):
    i = 0
    while i < len(theList):
        if theList[i] == x:
            return True
        i = i + 1
    return False

def binary_search(theList, x):
    lo = 0
    hi = len(theList)
    while lo < hi:
        mid = (lo + hi)/2
        if theList[mid] == x:
            return True
        if theList[mid] < x:
            lo = mid + 1
        else:
            hi = mid
    return False

print linear_search(["Apfel", "Pfirsich", "Birne"], "Apfel")
print linear_search(["Apfel", "Pfirsich", "Birne"], 7)

print binary_search([2, 5, 7, 11], 9)