factorial_memoization.cpp

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#include <iostream> // for std::cout
#include <cassert>  // For test cases
#include <array>    // For std::array
#include <cstdint>  // For uint64_t

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

namespace math {

uint64_t fact_recursion(uint64_t n) {
    if (n == 0) return 1;        // Base case: 0! = 1
    if (memo[n] != 0) return memo[n]; // Return already computed value
    memo[n] = n * fact_recursion(n - 1);    // Store and return the computed value
    return memo[n];
}
 
} // namespace math
void test_fact_recursion() {
    // 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";
}

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