How to Calculate Fibonacci with Dynamic Programming Caching

Here is how to calculate fibonacci with dynamic programming caching.
Run the program here: https://repl.it/@VinitKhandelwal/fibonacci-dynamic-programming

cal = 0

def slowFibonacci(n):

  global cal

  cal += 1

  if n<2:

    return n

  return slowFibonacci(n-1) + slowFibonacci(n-2)

cal2 = 0

cache = {}

def fastFibonacci(n):

  global cache, cal2

  if n in cache:

    return cache[n]

  else:

    cal2 += 1

    if n<2:

      return n

    cache[n] = fastFibonacci(n-1) + fastFibonacci(n-2)

    return cache[n]

print(f"Fibonacci without caching {slowFibonacci(30)}")

print(f"Calculated {cal} times")

print(f"Fibonacci without caching {fastFibonacci(30)}")

print(f"Calculated {cal2} times")

OUTPUT
Fibonacci without caching 832040
Calculated 2692537 times
Fibonacci without caching 832040
Calculated 32 times

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