lec5.12-fibMetered.py

# lec5.12-fibMetered.py
# edX MITx 6.00.1x
# Introduction to Computer Science and Programming Using Python
# Lecture 5, video 12

# Introduction to global variables
# Use with care, destroys locality of code
# and makes it easier to introduce bugs

def fibMetered(x):
    global numCalls
    numCalls += 1
    if x == 0 or x == 1:
        return 1
    else:
        return fibMetered(x-1) + fibMetered(x-2)


def testFib(n):
    for i in range(n+1):
        global numCalls
        numCalls = 0
        print('fib of ' + str(i) + ' = ' + str(fibMetered(i)))
        print('fib called ' + str(numCalls) + ' times')


# Example calls to testFib()
testFib(5)
print ''
testFib(20)