factorial_memoization.cpp File Reference

Factorial calculation using recursion and memoization More...

#include <iostream>
#include <cassert>
#include <array>
#include <cstdint>

Include dependency graph for factorial_memoization.cpp:

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Namespaces
namespace	math
	for assert

Functions
uint64_t	math::fact_recursion (uint64_t n)
	Computes the factorial of a non-negative integer using recursion and memoization.
void	test_fact_recursion ()
	Self-test implementations for the fact_recursion function.
int	main ()
	Main function to run test cases and interact with the user.

Variables
std::array< uint64_t, 1000 >	memo {0}
	Array to store computed factorials for memoization.

Detailed Description

Factorial calculation using recursion and memoization

This program computes the factorial of a non-negative integer using recursion with memoization (top-down dynamic programming). It stores intermediate results to avoid redundant calculations for improved efficiency.

Memoization is a form of caching where the result to an expensive function call is stored and returned. Example: Input: n = 5 Output: 120

Explanation: 5! = 5 × 4 × 3 × 2 × 1 = 120

The program uses a recursive function fact_recursion which caches computed results in a memo array to avoid recalculating factorials for the same numbers.

Time Complexity: O(n) Space Complexity: O(n)

Author

Vedant Mukhedkar

Definition in file factorial_memoization.cpp.

Function Documentation

main()

int main

(

void

)

Main function to run test cases and interact with the user.

Returns

0 on program success

Definition at line 69 of file factorial_memoization.cpp.

           {
    // Run test cases
    test_fact_recursion();
    return 0;
}

test_fact_recursion()

void test_fact_recursion

(

)

Self-test implementations for the fact_recursion function.

Returns

void

Definition at line 56 of file factorial_memoization.cpp.

                           {
    // Test cases for factorial computation
    assert(math::fact_recursion(0) == 1);
    assert(math::fact_recursion(1) == 1);
    assert(math::fact_recursion(5) == 120);
    assert(math::fact_recursion(10) == 3628800);
    std::cout << "All test cases passed!\n";
}

Variable Documentation

memo

std::array<uint64_t, 1000> memo {0}

Array to store computed factorials for memoization.

Definition at line 31 of file factorial_memoization.cpp.

{0};