In C++, difftime() function is defined in ctime header file. The difftime() function is used to calculate the difference between two times in a second. The function receives two time_t type inputs and calculates the difference between them.
Syntax of difftime()
double difftime(time_t end, time_t start);
Parameters
This method accepts two parameters:
start: time_t object for start time. end: time_t object for end time.
Returns: This function returns the difference between two times in seconds.
Example of difftime() function
Below is the C++ program to demonstrate difftime() function:
C++
// C++ program to demonstrate // example of difftime() function. #include <bits/stdc++.h> using namespace std;
// Driver code int main()
{ time_t start, ending;
long addition;
time (&start);
for ( int i = 0; i < 20000; i++) {
for ( int j = 0; j < 20000; j++);
}
for ( int i = 0; i < 20000; i++) {
for ( int j = 0; j < 20000; j++);
}
for ( int i = 0; i < 20000; i++) {
for ( int j = 0; j < 20000; j++);
}
time (&ending);
cout << "Total time required = "
<< difftime (ending, start) << " seconds " << endl;
return 0;
} |
Output:
Total time required = 2 seconds
The complexity of the above method
Time Complexity: O(n^2) where n is 20000.
Auxiliary Space: O(1)