417d3b5fff
The bottom-up solution run in O(n) time instead of O(2^n) time, which the
recursive solution runs as:
```
def fib(n):
return fib(n - 2) + fib(n - 1)
```
Remember that exponential algorithms are usually recursive algorithms with
multiple sibling calls to itself.
6 lines
122 B
Python
6 lines
122 B
Python
def fib(n):
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cache = (0, 1)
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for _ in range(n):
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a, b = cache
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cache = (b, a + b)
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return cache[0]
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