View difference between Paste ID: 4LX9h6D4 and DRz3FpEz

 #include <ctime>
 #include <iostream>
 #include "mpirxx.h"
 
 template<int N> mpz_class fib(mpz_class& tmp)
 {
     mpz_class t; tmp = fib<N - 1>(t);
     return tmp + t;
 }
 
 template<> mpz_class fib<1>(mpz_class& tmp) { tmp = 0; return 1; }
 template<> mpz_class fib<2>(mpz_class& tmp) { tmp = 1; return 1; }
 template<int N> mpz_class fib() { return fib<N>(mpz_class()); }
 
 int main()
 {
     clock_t t_start = clock();
     std::cout << fib<1000>() << std::endl;
     printf("Time: %.3fs\n", (float)(clock() - t_start) / 1000);
     return 0;
 }
 
 /*
 Output:
-434665576869374564356885276750406258025646605173717804024817290895365554179490518904038798400792551692959225930803
+43466557686937456435688527675040625802564660517371780402481729089536555417949051890403879840079255169295922593080
-22634775209689623239873322471161642996440906533187938298969649928516003704476137795166849228875
+322634775209689623239873322471161642996440906533187938298969649928516003704476137795166849228875
 Time: 0.001s
 */