factorial

Factorial Sequence

This exercise is the most famous exercises to explain how Recursion works.

This exercise was resolved generating 5 ways:

• For Loop.
• Recursion.
• Recursion with static variable.
• Dynamic Programming using the bottom-up strategy.
• Dynamic Programming using the top-down strategy.

How to compile:

make

Exercise Table:

N	Exercise	Description	Efficiency	Run
1	For Loop	Factorial using for loop with accumulator variable.	EXCELLENT	./for_factorial N
2	Recursion	Factorial using recursion.	GOOD	./recursive_factorial N
3	Recursion with static variable	Factorial using recursion with static variable.	GOOD	./static_factorial N
4	Dynamic Programming using the Bottom-Up strategy	Factorial using DP where you construct the solution in an array.	REGULAR	./dp_bottom_up_factorial N
5	Dynamic Programming using the Top-Down strategy	Factorial using DP where you construct the solution using memoization.	EXCELLENT	./dp_top_down_factorial N

Topics, Concepts and References of Interest:

Topic	Link
Factorial	https://en.wikipedia.org/wiki/Factorial
Recursion	https://en.wikipedia.org/wiki/Recursion_(computer_science)
Memoization	https://en.wikipedia.org/wiki/Memoization
Dynamic Programming	https://en.wikipedia.org/wiki/Dynamic_programming
Top-down and Bottom-up design	https://en.wikipedia.org/wiki/Top-down_and_bottom-up_design