Source of timing_summation4.cpp

Structures and functions

  1: //timing_summation4.cpp
  2: //Finds the sum of integers over a given range.
  3: //Allows us to measure the *relative* time taken to sum the integers
  4: //over ranges of various sizes by introducing an artificial delay into
  5: //each step of the computation, and uses a Stopwatch class object to
  6: //start and stop a "timer" which has appropriate interface functions
  7: //for our purposes.

  9: #include <iostream>
 10: using namespace std;

 12: #include "utilities.h"
 13: using Scobey::Pause;
 14: using Scobey::Stopwatch;

 16: int main(int)
 17: {
 18:     cout << "\nThis program computes the sum of all integers in a "
 19:         "user-chosen range, and\nattempts to compute as well the time "
 20:         "taken to perform the summation.\n";
 21:     Pause();

 23:     cout << "Enter the smaller integer, then the larger: ";
 24:     int small, large;
 25:     cin >> small >> large;  cin.ignore(80, '\n');  cout << endl;

 27:     int sum = 0;
 28:     Stopwatch timer;
 29:     timer.start();
 30:     for (int numberToAdd=small; numberToAdd<=large; numberToAdd++)
 31:     {
 32:         sum += numberToAdd;
 33:         timer.delay();
 34:     }
 35:     timer.stop();

 37:     cout << "The sum of all integers from " << small << " to "
 38:         << large << " (inclusive) is " << sum << ".\n";
 39:     cout << "The amount of time taken to add them up was " 
 40:         << timer.getSeconds() << " seconds.\n";
 41:     Pause();
 42: }