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difftime

  • 项目

Finds the difference between two times.

doubledifftime(time_ttimer1**,time_ttimer0);**

Routine Required Header Compatibility
difftime <time.h> ANSI, Win 95, Win NT

For additional compatibility information, see Compatibility in the Introduction.

Libraries

LIBC.LIB Single thread static library, retail version
LIBCMT.LIB Multithread static library, retail version
MSVCRT.LIB Import library for MSVCRT.DLL, retail version

Return Value

difftime returns the elapsed time in seconds, from timer0 to timer1. The value returned is a double-precision floating-point number.

Parameters

timer1

Ending time

timer0

Beginning time

Remarks

The difftime function computes the difference between the two supplied time values timer0 and timer1.

Example

/* DIFFTIME.C: This program calculates the amount of time
 * needed to do a floating-point multiply 10 million times.
 */

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

void main( void )
{
   time_t   start, finish;
   long loop;
   double   result, elapsed_time;

   printf( "Multiplying 2 floating point numbers 10 million times...\n" );
  
   time( &start );
   for( loop = 0; loop < 10000000; loop++ )
      result = 3.63 * 5.27;
   time( &finish );

   elapsed_time = difftime( finish, start );
   printf( "\nProgram takes %6.0f seconds.\n", elapsed_time );
}

Output

Multiplying 2 floats 10 million times...

Program takes      2 seconds.

Floating-Point Support Routines |  Time Management Routines

See Also   time