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C++ measure execution time – How to Measure Execution Time in CPP?

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C++ measure execution time: In the previous article, we have discussed about Convert Set to Vector. Let us learn How to Measure Execution Time in C++ Program.

In this post, we will look at how to calculate the execution time of any procedure in C++.

We will calculate execution time in seconds,minutes,hours,milliseconds,microseconds etc.

Calculate Execution Time in C++

C++ measure execution time milliseconds: We often experience situations in which we need to measure the execution time of a large number of operations in order to evaluate results. As an example,

  • How long did it take to push data into a vector, and so on.
  • How much time was spent looking for data in a datastructure?
  • How long did it take to send or receive a message over the network, and so on.

We can use the boost::posix time::ptime and boost::posix time::time duration forms to accomplish this.

  • boost::posix_time::ptime denotes a specific time point.
  • boost::posix_time::time_duration denotes the length of time between two points.

To calculate execution time, we will retrieve the current time twice: once before and once after the process.

The difference between these two timestamps will give us the operation’s execution time, i.e.

  • Start_Time =Get present Time
  • Executing the code
  • End_Time=Get present Time
  • Time taken =End_Time-Start_Time

Assume our task is to insert 9000000  string values into string vector. Let’s look at how to calculate execution time using boost.

Below is the implementation:

#include <bits/stdc++.h>
#include <boost/date_time.hpp>
using namespace std;
int main()
{
    // Creating a string vector
    vector<string> stringvector;
    // Get present Time before the task gets executed
    boost::posix_time::ptime start_time
        = boost::posix_time::second_clock::local_time();
    // Adding 9000000 string values to vector
    for (int i = 0; i < 9000000; i++)
        stringvector.push_back(std::to_string(i));
    // get the time after the task gets executed
    boost::posix_time::ptime end_time
        = boost::posix_time::second_clock::local_time();
    // Get the time taken to execute the task by calculating
    // diffrence between end time and start time
    boost::posix_time::time_duration timetaken
        = end_time - start_time;
    cout << "Time taken = " << timetaken << endl;
    // Printing the time taken in other formats
    cout << "Time taken in hours : " << timetaken.hours()
         << endl;
    cout << "Time taken in minutes : "
         << timetaken.minutes() << endl;
    cout << "Time taken in seconds : "
         << timetaken.seconds() << endl;

    // Printing the time taken to execute the task  in total
    // seconds only
    cout << "Time taken in Total Seconds : "
         << timetaken.total_seconds() << endl;
    // Printing the time taken to execute the task  in total
    // milliseconds only
    cout << "Time taken in Total Milli Seconds : "
         << timetaken.total_milliseconds() << endl;
    // Printing the time taken to execute the task  in total
    // microseconds only
    cout << "Time taken in Total Micro Seconds : "
         << timetaken.total_microseconds() << endl;
    // Printing the time taken to execute the task  in total
    // nanoseconds only
    cout << "Time taken in Total Nano Seconds : "
         << timetaken.total_nanoseconds() << endl;
}

Output:

Time taken = 00:00:02
Time taken in hours : 0
Time taken in minutes : 0
Time taken in seconds : 2
Time taken in Total Seconds : 2
Time taken in Total Milli Seconds : 2000
Time taken in Total Micro Seconds : 2000000
Time taken in Total Nano Seconds : 2000000000

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