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  1. #include <iostream>
  2. #include <utility>
  3. #include <cassert>
  4.  
  5. using namespace std;
  6.  
  7. // return {fib_(n - 1), fib_n}
  8. pair<int, int> fib_impl(unsigned int n) {
  9.     if (n == 0) return {1, 0};
  10.     if (n == 1) return {0, 1};
  11.     auto p = fib_impl(n - 1);
  12.     return {p.second, p.first + p.second};
  13. }
  14.  
  15. int fib(unsigned int n) {
  16.     return fib_impl(n).second;
  17. }
  18.  
  19. int main() {
  20.     assert(fib(2) == 1);
  21.     assert(fib(10) == 55);
  22. }
  23.  
Success #stdin #stdout 0s 3292KB
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stdin 
Standard input is empty
stdout 
Standard output is empty
https://ideone.com/FlfqEp
language:
C++14 (gcc 8.3)
created:
12 years ago
visibility:
public

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