C program

EMPS intranet

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Value and type of last evaluated expression: Address of array element: Address of array elementx: (none)

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Code

 Header...
#define N 8
 int compared(const void *p1,const void *p2){
»  static int called;
»  
»  int x1=*(int *)p1, x2=*(int *)p2;

»  ++called;
»  if (x1<x2) 
    return -1;
»  return x1>x2;
}
 ... 


 int main(){
»  int x[N]={8,6,3,5,7,1,4,2};
»  qsort(x, N, sizeof *x, compared);
»  
»  for ( int i=0;i<N; ++i) 
    printf("%d\n", xi);

»  return 0;
}
 ...

Memory

Static variables
128	129	130	131
called = 0

compared()
264	265	266	267	268	269	270	271
p2 = 840				p1 = 836
272	273	274	275	276	277	278	279
?	?	?	?	x1 = 3
280	281	282	283
x2 = 5

compared()
264	265	266	267	268	269	270	271
p2 = 832				p1 = 828
272	273	274	275	276	277	278	279
?	?	?	?	x1 = 8
280	281	282	283
x2 = 6

compared()
264	265	266	267	268	269	270	271
p2 = 856				p1 = 852
272	273	274	275	276	277	278	279
?	?	?	?	x1 = 4
280	281	282	283
x2 = 2

compared()
264	265	266	267	268	269	270	271
p2 = 848				p1 = 844
272	273	274	275	276	277	278	279
?	?	?	?	x1 = 7
280	281	282	283
x2 = 1

compared()
344	345	346	347	348	349	350	351
p2 = 852				p1 = 848
352	353	354	355	356	357	358	359
?	?	?	?	x1 = 7
360	361	362	363
x2 = 2

compared()
344	345	346	347	348	349	350	351
p2 = 836				p1 = 828
352	353	354	355	356	357	358	359
?	?	?	?	x1 = 6
360	361	362	363
x2 = 3

compared()
344	345	346	347	348	349	350	351
p2 = 852				p1 = 844
352	353	354	355	356	357	358	359
?	?	?	?	x1 = 1
360	361	362	363
x2 = 2

compared()
344	345	346	347	348	349	350	351
p2 = 856				p1 = 848
352	353	354	355	356	357	358	359
?	?	?	?	x1 = 7
360	361	362	363
x2 = 4

compared()
344	345	346	347	348	349	350	351
p2 = 840				p1 = 828
352	353	354	355	356	357	358	359
?	?	?	?	x1 = 6
360	361	362	363
x2 = 5

compared()
424	425	426	427	428	429	430	431
p2 = 856				p1 = 832
432	433	434	435	436	437	438	439
?	?	?	?	x1 = 5
440	441	442	443
x2 = 7

compared()
424	425	426	427	428	429	430	431
p2 = 856				p1 = 840
432	433	434	435	436	437	438	439
?	?	?	?	x1 = 8
440	441	442	443
x2 = 7

compared()
424	425	426	427	428	429	430	431
p2 = 852				p1 = 828
432	433	434	435	436	437	438	439
?	?	?	?	x1 = 3
440	441	442	443
x2 = 4

compared()
424	425	426	427	428	429	430	431
p2 = 852				p1 = 832
432	433	434	435	436	437	438	439
?	?	?	?	x1 = 5
440	441	442	443
x2 = 4

compared()
424	425	426	427	428	429	430	431
p2 = 856				p1 = 836
432	433	434	435	436	437	438	439
?	?	?	?	x1 = 6
440	441	442	443
x2 = 7

compared()
424	425	426	427	428	429	430	431
p2 = 844				p1 = 828
432	433	434	435	436	437	438	439
?	?	?	?	x1 = 3
440	441	442	443
x2 = 1

compared()
424	425	426	427	428	429	430	431
p2 = 848				p1 = 828
432	433	434	435	436	437	438	439
?	?	?	?	x1 = 3
440	441	442	443
x2 = 2

compared(): for()
824	825	826	827
i = 0
main()
				828	829	830	831
				x[0] = 8
832	833	834	835	836	837	838	839
x[1] = 6				x[2] = 3
840	841	842	843	844	845	846	847
x[3] = 5				x[4] = 7
848	849	850	851	852	853	854	855
x[5] = 1				x[6] = 4
856	857	858	859
x[7] = 2

NB: the actual memory address of each variable is the
address shown plus 4293884016 (0xFFEF7870).

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Output

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Try stepping through the code

Code

Static variables

compared()

compared()

compared()

compared()

compared()

compared()

compared()

compared()

compared()

compared()

compared()

compared()

compared()

compared()

compared()

compared()

compared(): for()

main()

Output