ex4_cond.c File Reference

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

Go to the source code of this file.

Macros
#define	SIZE   100000000
#define	GET_SEC(a, b)   ((b - a) / (double)CLOCKS_PER_SEC)

Functions
static int	cmp_dbl (const void *a, const void *b)
int	main (int argc, char **argv)

Macro Definition Documentation

#define GET_SEC	(		a,
			b
	)		((b - a) / (double)CLOCKS_PER_SEC)

Definition at line 7 of file ex4_cond.c.

#define SIZE   100000000

Definition at line 5 of file ex4_cond.c.

Function Documentation

static int cmp_dbl ( const void *  a, const void *  b  )

static

Definition at line 9 of file ex4_cond.c.

{
   const double* aa = a;
   const double* bb = b;

   if (aa < bb)
      return -1;
   if (aa > bb)
      return 1;
   return 0;
}

int main	(	int	argc,
		char **	argv
	)

Definition at line 21 of file ex4_cond.c.

{
   clock_t start;
   int* x = malloc(SIZE * sizeof(*x));
   double  sum;
   int     q;
   
   for(int i = 0; i < SIZE; i++)
      x[i] = (rand() % 256);
   
   sum = 0.0; start = clock();

   /* In order 1 */
   for(int i = 0; i < SIZE; i++)
      sum += x[i];

   printf("IO time=%.3f sum=%.1f\n", GET_SEC(start, clock()), sum);

   sum = 0.0; start = clock(); q = 0;

   /* In order 1 */
   for(int i = 0; i < SIZE; i++)
      if (x[i] <= 128)
         sum += x[i];
      else
         q++;

   printf("IO time=%.3f sum=%.1f %d\n", GET_SEC(start, clock()), sum, q);

   qsort(x, SIZE, sizeof(*x), cmp_dbl);
   
   sum = 0.0; start = clock(); q = 0;

   /* In order 1 */
   for(int i = 0; i < SIZE; i++)
      if (x[i] <= 128)
         sum += x[i];
      else
         q++;

   printf("IO time=%.3f sum=%.1f %d\n", GET_SEC(start, clock()), sum, q);

}