fork(8) download
copy 
  1. //
  2. //  main.cpp
  3. //  Memoizator
  4. //
  5. //
  6. #include <iostream>
  7. #include <map>
  8. #include <tuple>
  9. #define MEMOIZATOR(N, R, ...)                               \
  10. R _ ## N (__VA_ARGS__);                                     \
  11. std::map<std::tuple<__VA_ARGS__>, R> _memo_ ## N;           \
  12. template <typename ... Args>                                \
  13. R N (Args ... args) {                                       \
  14.     auto& _memo = _memo_ ## N;                              \
  15.     auto result = _memo.find(std::make_tuple(args...));     \
  16.     if (result != _memo.end()) {                            \
  17.         return result->second;                              \
  18.     }                                                       \
  19.     else {                                                  \
  20.         auto result = _ ## N  (args...);                    \
  21.         _memo[std::make_tuple(args...)] = result;           \
  22.         return result;                                      \
  23.     }                                                       \
  24. }    
  25. MEMOIZATOR(fibonacci, long int, int);
  26.  
  27. int function_count = 0;
  28.  
  29. long int _fibonacci(int n) {
  30. 	function_count++;
  31.     if (n == 1 or n == 2) {
  32.         return 1;
  33.     }
  34.     return fibonacci(n - 1) + fibonacci(n - 2);
  35. }
  36.  
  37. using namespace std;
  38. int main(int argc, const char * argv[]) {
  39.     // insert code here...
  40.     cout << "Result: " << fibonacci(40) << endl;
  41.     cout << "Fibonacci executed " << function_count << " times." <<endl;
  42.     return 0;
  43. }
  44.  
  45.  
Success #stdin #stdout 0s 3232KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Result: 102334155
Fibonacci executed 40 times.
https://ideone.com/C3JEUT
language:
C++14 (gcc 8.3)
created:
8 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!