hell1+3.cpp

// Only implements the caching of hell3.cpp without the avx bulls**t.
// Some benches for my CPU (3600X) (-Ofast)

// 477 microseconds, 449 microseconds, 428 microseconds, 885 microseconds
#include <chrono>
#include <iostream>
#include <unordered_map>

std::unordered_map<int, long long int> cache;

void sum_up_to_n(int n) {
  if (cache.find(n) != cache.end()) {
    std::cout << "Sum of integers up to " << n << ": " << cache[n] << '\n';
    return;
  }

  // Initialize sum variable
  long long int sum = 0;

  // Loop through integers from 1 to n
  for (int i = 1; i <= n; ++i) {
    // Add current integer to sum
    sum += i;
  }

  cache[n] = sum;

  std::cout << "Sum of integers up to " << n << ": " << sum << '\n';
}

int main() {
  auto start = std::chrono::high_resolution_clock::now();

  int nums[] = {
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000,
      100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000, 100000};
  for (int num : nums)
    sum_up_to_n(num);

  auto end = std::chrono::high_resolution_clock::now();

  auto duration =
      std::chrono::duration_cast<std::chrono::microseconds>(end - start)
          .count();

  std::cout << "Program finished in " << duration << " microseconds."
            << std::endl;
  return 0;
}