Function Timing

#include <iostream>
#include <fstream>
 
#include <ctime>
#include <chrono>
 
using std::cout;
using std::endl;
using std::chrono::time_point;
using std::chrono::system_clock;
using std::chrono::duration;

int main(){
 
        int pause;
        int time;
        bool running = true;
 
        do {
               
                double numberOfRuns = 0;
 
                cout << "Hello Welcome to the function tester." << endl;
       
                cout << "How many seconds would you like to test for? ( 0 to quit )" << endl;
 
                std::cin >> time;
       
                //Exit Program Condition
                if(time)
                {
                        time_point<system_clock> start, end;
                        start = system_clock::now();
                        duration<double> elapsed_seconds;
       
                        while(elapsed_seconds.count() < time){
       
                                //INSERT FUNCTION YOU WANT TO TIME HERE
                                //int i = 0;
                                //i = 1 + 1; ???
                                //do you mean int i = 0; ++i; ??
                                int i = 2;
                                //INSERT FUNCTION YOU WANT TO TIME UP THERE
 
 
                                ++numberOfRuns;
                               
                                //Update timing
                                end = system_clock::now();
                                elapsed_seconds = end - start;
                        }                      
 
 
                        //Output Data
                        cout << "elapsed time is : " << elapsed_seconds.count() << endl;
                        cout << "Number of runs is : " << numberOfRuns << endl << endl;                        
 
                        cout << "Average runs per second is : " << numberOfRuns / elapsed_seconds.count() << endl;
                        cout << "Average runs per frame at 60 FPS is : " << (numberOfRuns / elapsed_seconds.count()) / 60 << endl;
                        cout << "One execution takes : " << elapsed_seconds.count() / numberOfRuns << "seconds." << endl << endl;
                        cout << "Press 1 to continue" << endl;
                        std::cin >> pause;
 
                        //Clear Screen
                        for (int i = 0; i != 50; ++i){
                                cout << endl;
                        }
                        //or system('cls') in windows or system('clear') in linux
                } else {
                        running = false
                };
        } while(running)                              
 
        return 0;
};