# Timing homework • ### Question

• Last week our class was given the folllowing instructions to do a program:

o   Input range of N values

o   Create range_time_vector

o   Input number_of_cases

o   for each input in the range of inputs

·         Set time_sum to zero

·         Set time_average to zero

·         For each case

§  Start the time

§  Execute the loop

§  End the time

§  Add the time difference to time_sum

o   Calculate time_average = time_sum/ number_of_cases

o   Store time_average in range_time_vector at input index

So far I've been able to do this much:

#include <iostream>
#include <vector>

using namespace std;

int main ()
{
int N =0;
int Range=0;
int NumberOfCases=0;
cout << "Enter N" <<endl;
cin >> N;
cout << "Enter Range" <<endl;
cin >> Range;
cout << "Number of cases" <<endl;
cin >> NumberOfCases;
vector<double> range_time_Vector(Range);
int K = N;
for(int i=0; i < Range; ++i)
{
double time_sum = 0.0;
double time_average = 0.0;
for (int m=1 ; m <= NumberOfCases; ++m)
{
cout << "for m=" << m << "  K=" << K << endl;
}
}
return 0;
}

Can Someone help me with the following steps:
For each case

§  Start the time

§  Execute the loop

§  End the time

§  Add the time difference to time_sum

o   Calculate time_average = time_sum/ number_of_cases

o   Store time_average in range_time_vector at input index

I tried googling and going to cplusplus.com, but wasn't able to find anything to help me with my program.

• Changed type Wednesday, March 10, 2010 5:35 PM
Tuesday, March 9, 2010 3:20 PM

• Well, to calculate time, you have a couple of options.  std::clock() can be used to get "ticks" that have elapsed since your program began.  The resolution may not be what you need.  You get CLOCKS_PER_SEC "ticks" every second (this is 1000 in VS2008).

If you want to use Microsoft specific code, try QueryPerformamceCounter and QueryPerformanceFrequency for high-precision timing.
• Marked as answer by Tuesday, March 16, 2010 5:33 AM
Tuesday, March 9, 2010 3:48 PM

### All replies

• > Can Someone help me with the following steps:

These forums aren't really for homework assignments, however here's some
hints that may get you a bit futher ;)

> § Start the time

I'd replace the above with "get the current time" (and save it)

> § End the time

Get the time now.

Dave
Tuesday, March 9, 2010 3:47 PM
• Well, to calculate time, you have a couple of options.  std::clock() can be used to get "ticks" that have elapsed since your program began.  The resolution may not be what you need.  You get CLOCKS_PER_SEC "ticks" every second (this is 1000 in VS2008).

If you want to use Microsoft specific code, try QueryPerformamceCounter and QueryPerformanceFrequency for high-precision timing.
• Marked as answer by Tuesday, March 16, 2010 5:33 AM
Tuesday, March 9, 2010 3:48 PM