print the number of operations and time taken to compute Fibonacci numbers - c++

Question

How would I print the number of operations and time taken to compute Fibonacci numbers recursively versus that needed to compute them iteratively. Here is my code currently:
#include<bits/stdc++.h>
using namespace std;
int iterative(int n){
int num1 = 0, num2 = 1, num3, j;
cout<<num1<<" "<<num2<< " ";
if( n == 0)
return num1;
for (j = 2; j <= n; j++){
num3 = num1 + num2;
cout<<num3<<" ";
num1 = num2;
num2 = num3;
}
return num2;
}
int recursive(int num){
if (num <= 1)
return num;
return recursive(num-1) + recursive(num-2);
}
int main (){
// main method to test the function
int n;
cout << "Enter a value for n: ";
cin >> n;
printf("\nWhen n is %d ,the iterative method number is : %d", n,iterative(n));
getchar();
printf("\nWhen n is %d ,the recursive method number is : %d", n,recursive(n));
getchar();
return 0;
}

Answer 1

Try something like this. As mentioned above you should not using include #include<bits/stdc++.h> . If you want to know more about problems with that include you should read this.
#include <chrono>
#include <iostream>
int iterative(int n, int &cnt){
int num1 = 0, num2 = 1, num3, j;
std::cout<<num1<<" "<<num2<< " ";
if( n == 0)
return num1;
for (j = 2; j <= n; j++){
num3 = num1 + num2;
std::cout<<num3<<" ";
num1 = num2;
num2 = num3;
cnt++;
}
return num2;
}
int recursive(int num, int &cnt){
if (num <= 1)
return num;
cnt++;
return recursive(num-1, cnt) + recursive(num-2, cnt);
}
int main (){
// main method to test the function
int n;
int cnt = 0;
std::cout << "Enter a value for n: ";
std::cin >> n;
auto start = std::chrono::high_resolution_clock::now();
int iterativeNum = iterative(n, cnt);
auto end = std::chrono::high_resolution_clock::now();
std::chrono::duration<float> duration = end - start;
printf("\nWhen n is %d , num of operation is : %d , time spent is : %f , the iterative method number is : %d", n, cnt, duration.count() ,iterativeNum);
getchar();
cnt = 0;
start = std::chrono::high_resolution_clock::now();
int recNum = recursive(n, cnt);
end = std::chrono::high_resolution_clock::now();
duration = end - start;
cnt = 0;
printf("\nWhen n is %d , num of operation is : %d , time spent is : %f , the recursive method number is : %d" , n, cnt, duration.count(), recNum);
getchar();
return 0;
}