What are some examples of memoization in code?

What are some examples of memoization in code?

Memoization is an optimization technique used to speed up function calls by caching previously computed results. For example, in a Fibonacci sequence calculation, you can store the results of each Fibonacci number to avoid redundant calculations.

Can you show me a code example in Python?

Sure! Here's a simple Python example using a decorator for memoization:

def memoize(func):
    cache = {}
    def wrapper(n):
        if n not in cache:
            cache[n] = func(n)
        return cache[n]
    return wrapper

@memoize
def fibonacci(n):
    if n <= 1:
        return n
    return fibonacci(n-1) + fibonacci(n-2)

How does this improve performance?

By caching the results of expensive function calls, memoization reduces the number of times the function needs to be executed, leading to significant performance improvements, especially in recursive functions like Fibonacci.