Question 1.


void
func( int * ptr )
{
  ptr++;
  ptr += 1;     
}

int
main ()
{
  int arr[] = {0,0};
  int * p = arr;
  func(p);  
  p++;
  *p += 1;
  printf("%d %d\n",arr[1],arr[0]);
}


The main above will print: ______________




Question 2.

Consider the following makefile:

data.o: data.c data.h
	gcc -c data.c

driver.o: driver.c data.h
	  gcc -c driver.c

io.o: io.c
      gcc -c io.c

driver: io.o data.o driver.o
	gcc -o driver io.o driver.o data.o

Running ls -ls we get:

-rw-r--r-- 1 plab courses 673 Feb 4 18:10 data.c
-rw-r--r-- 1 plab courses 673 Feb 4 16:59 data.h
-rw-r--r-- 1 plab courses 673 Feb 4 17:00 data.o
-rwxr-xr-x 1 plab courses 673 Feb 4 18:01 driver
-rw-r--r-- 1 plab courses 673 Feb 4 17:30 driver.c
-rw-r--r-- 1 plab courses 673 Feb 4 17:31 driver.o
-rw-r--r-- 1 plab courses 673 Feb 4 17:40 io.c
-rw-r--r-- 1 plab courses 673 Feb 4 17:41 io.o

Running the command 'make driver' will re-create the following files (mark
all true answers, you can mark between 0 and 5 answers):
1. driver
2. driver.o
3. data.h
4. data.o
5. io.o



Question 3.

#define MAX(a,b) ( ( (a) > (b) ) ? (a) : (b) )

int i=2;
int j=3;
int x = MAX(i++,j);
printf("%d %d\n",i,x);

the  output of this code is: ______________



Question 4.


Consider the command:
   g++ ex0.o stack.c -o ex0

1. The command performs compilation and linkage, but doesn't perofrm
   preprocessing.
2. The command only performs compilation.
3. The command only performs linkage.
4. The command performs both linkage and compilation



Question 5.

#include <stdio.h>

void
f(int* pa[])
{
  for (int i=0; i<5; i++)
  {
     pa[i] = (int*)malloc(7*sizeof(int));
  }
}

int main()
{
  int* pa[5];

  for( int i=0; i<5; i++ )
   pa[i] = (int*)malloc(7*sizeof(int));

  f(pa);

  for (int i=0; i<5; i++)
    free(pa[i]);
}

1. The program causes runtime error.
2. The program has a memory leak.
3. The program will not compile.
4. All the above are incorrect



Question 6.


Assume that sizeof(char)=1, sizeof(int)=4, and sizeof(void*)=4

struct Str1 {
       int x;
       char y[8];
};
 
struct Str2 {
       int x[2];
       char *y;
};  

sizeof(Str1) - sizeof(Str2) = _____________



Question 7.


struct Flight {
  char source[20];
  char * destination;
};

Flight ticket1;
Flight ticket2;
ticket1.destination = (char*)malloc( 20*sizeof(char) );
strcpy(ticket1.source, "florence");
strcpy(ticket1.destination,"london");
ticket2=ticket1;
*(ticket2.destination + 2) = 'k';
ticket2.source[1] = 'm';

printf("%s %s",ticket1.source,ticket2.destination);

the output of the code will be: _______________________



Question 8.


#define BAR(x) x )
#define FOO(x) ( x++

int a = 2;
int b = 3;
int c =  FOO(a) + BAR(b);

1. This code will generate a compilation error.
2. This code will generate a run-time error.
3. The code will compile without problems.
4. This code will generate a pre-processing error.




Question 9.

#include <stdio.h>
#include <malloc.h>

void
f(int* pa)
{
   static int* pb = NULL;
   if (pb != NULL) {
      (*pb)++;
   }
   pb = pa++;
}

int main()
{
   int a[5];
   for (int i=0; i<5; i++)
     a[i] = i;
   for (int i=0; i<2; i++)
     f(a + i);
   for (int i=0; i<5; i++)
     printf("%d ", a[i]);
   printf("\n");
}

1. The program does not compile
2. The output is: 0 1 2 3 4
3. The output is: 1 1 2 3 4
4. The output is: 1 2 3 4 4



Question 10.


Suppose that sizeof(char) = 1, sizeof(int) = 4, sizeof(double)=8.

union ID {
      char x;
      double y;
};

sizeof( ID ) is ________________



Question 11.


file1.h
---------------
#if !defined(FILE1_H)
#define FILE1_H

int x=7;

#endif

//end file1.h

file2.h
--------------
#if !defined(FILE2_H)
#define FILE2_H

#include "file1.h"

int x=8;

#endif

//end file2.h

file3.c
--------------
#include "file1.h"
#include "file2.h"

int main() {
    printf("%d",x);
    return 0;
}

//end file3.c

The command "gcc file3.c -o prog" will result:

1. no error/warning will be generated
2. error/warning in the pre-processing stage
3. error/warning in the compilation stage
4. error/warning in the linkage stage


Question 12.


   void main()
   {
(1)  int *y = (int*)malloc( 3*sizeof(int) );
(2)  int x[] = {1,2,3};
(3)  int ** pp = NULL;
(4)  int *z = y;  
   }

A space on the memory heap was allocated in the following lines (mark
all correct answers, between 0-4): 
a. 1
b. 2
c. 3
d. 4



Question 13.


   void
   foo( int const* r )
   {
(1)  (*r)++;
   }

   void
   bar( int const *p )
   {
(2)  printf("%d\n", *p );
   }
   
   void
   apple( int const* q )
   {
(3)  q++;
   }
   
   
   int
   main()
   {
     int x = 3;
     int y = 3;
   
(4)  foo(&x);
(5)  x++;
(6)  bar(&y);
(7)  apple(&x);
   }

Compilation errors were generated on the following lines (mark
all correct answers, between 0-7): 
a. 1
b. 2
c. 3
d. 4
e. 5
f. 6
g. 7



Question 14.


char s[] = {'p','l','a','b'};

What will be returned by calling strcmp(s,"plab")?

1. a negative number
2. 0
3. a positive number
4. We cannot know for sure



Question 15.


struct IntList {
  int value;
  IntList* next;
};

int
Last( IntList *L )
{
  for( ;  L->next != NULL; L = L->next )
    ;

  return L->value;    
}

main()
{
  IntList *p = (IntList*)malloc(sizeof(IntList));
  int x = Last(p);
}

1. This code will link errors
2. This code will generate compilation errors
3. The code will compile, but we canont predict what happens at run-time.
4. The code will generate run-time error.


Question 16.


void bar(int * x) {
  x[0] += 2;
}

void foo( int * x ) {
  x[1] += 2;
}

typedef void (*myfunc)(int*);

main()
{
  myfunc funcs[2] = { foo, bar };
  int arr[] = {3,4,5};
  (funcs[0])(arr);
  (funcs[1])(arr+1);

  printf("%d %d %d\n",arr[2],arr[1],arr[0]);
}

The output of the code is: __________________



Question 17.


int
cmp( void const* p, void const *q )
{
  return *(int const*)p - *(int const*)q;
}

int arr[] = { 1, 4, 5, 2 };
qsort( arr, 4, sizeof(int), cmp );

1. After running this code arr = { 5, 4, 2, 1 };
2. After running this code arr = { 1, 2, 4, 5 };
3. The code will not compile
4. The code will compile, but we cannot be sure about the content of
arr after running it


Question 18.


(1) int i;
(2) int * const px = &i;
(3) int j = 5;
(4) px = &j;
(5) px[1] = j;

1. Line 2 will generate compilation errors/warnings
2. Line 4 will generate compilation errors/warnings
3. Line 5 will generate compilation errors/warnings
4. The code will not generate compilation errors/warnings



Question 19.


(1) char s[] = "plab";
(2) (*s)++;
(3) *(s+2) = '\0';

1. line 2 will generate a compilation error
2. line 3 will generate a compilation error
3. after runnung this code the string s is "ql"
4. after runnung this code the string s is "pl"
5. after running this code the string s is "plab"



Question 20.


In a directory we have the following 2 files:

-rw-r--r--    1 plab     ntp          2306 Oct 30 07:54 list.c
-rw-r--r--    1 plab     ntp          2387 Oct 28 10:51 main.c

In main.c we use functions implemented in list.c.
The first line of main.c is: #include "list.c"

The result of running

   g++ main.c

is:

1. the preprocessor will report an error
2. the program will not compile
3. no problems in the compilation phase, but linkage will not work
4. a.out will be created



Question 21.


int y = 7;
int x = 18;

printf("--%2d--%4d--\n", x, y );

The output of this code is:

1. -- 7--  18--
2. --18--   7--
3. --18--7 --
4. --7--  18--



Question 22.



int *ip = (int*)malloc(100*sizeof(int));
(*ip) += 30;
free(ip);

1. This code will generate a compilation error.
2. This code can generate unpredictable run-time behavior.
3. No error would occur if we only check if ip equals NULL before calling
the "free" function
4. The code contains no error.