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03.py
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03.py
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# Return
def end(n, d):
"""Print the final digits of N in reverse order until D is found.
>>> end(34567, 5)
7
6
5
"""
while n > 0:
last, n = n % 10, n // 10
print(last)
if d == last:
return None
def search(f):
"""Return the smallest non-negative integer x for which f(x) is a true value."""
x = 0
while True:
if f(x):
return x
x += 1
def is_three(x):
"""Return whether x is three.
>>> search(is_three)
3
"""
return x == 3
def square(x):
return x * x
def positive(x):
"""A function that is 0 until square(x)-100 is positive.
>>> search(positive)
11
"""
return max(0, square(x) - 100)
# https://www.youtube.com/watch?v=QIh6CyrWhvw&list=PLx38hZJ5RLZfaBTgnl9EdoB3JqZl5c8G3&index=6
def invert(f):
"""Return a function g(y) that returns x such that f(x) == y.
>>> sqrt = invert(square)
>>> sqrt(16)
4
"""
return lambda y: search(lambda x: f(x) == y)