Question 1
1 #include "stdio.h"
2
3 #define N 5
4 int Weight[N] = { 3, 1, 4, 5, 2 };
5
6 int rand_choice()
7 {
8 int i, choice = 0;
9 int k = rand() % (3*N);
10 for( i = 0; i <= N; i++ ) 11 {
12 if( k >= 0 ) choice = i;
13 k -= Weight[i];
14 }
15 return choice;
16 }
17 int voting_machine( int vote )
18 {
19 if( vote == 1 ) return rand_choice();
20 else return vote;
21 }
Question 2
1 #include "stdio.h"
2
3 class Animal
4 { public:
5 virtual void init() {}
6 Animal() { init(); }
7 };
8
9 class GroundHog : public Animal
10 { public:
11 const char *appears;
12 virtual void init() { appears = "Feb 2"; }
13 };
14
15 int main()
16 {
17 GroundHog x;
18 printf( "Ground hogs appear %s\n" , x.appears );
19 return 0;
20 }
Question 3
1 #include "stdio.h"
2
3 const int march[31] = {
4 8, 5, 7, 2, -4, -14, -7, -4, -2, 0,
5 0, 2, 5, 7, 2, -4, -14, -7, -4, -2,
6 1, 7, 2, 2, -2, -3, -4, 6, -4, 3, 9 };
7
8 int main()
9 {
10 unsigned i, count = 31;
11 int sum = 0;
12
13 for( i = 0; i < style=""> {
15 sum += march[ i ];
16 }
17 printf( "The average low temperature in March was"
18 " %d degrees\n", sum / count );
19 return 0;
20 }
1 #include "stdio.h"
2 class R
3 {
4 public:
5 int k, depth;
6 R() :k(0), depth(0) {}
7 const R& operator=( const R & r )
8 {
9 if( this != &r )
10 { k = r.k; depth = r.depth+1; }
11 return r;
12 }
13 };
14 int main()
15 {
16 R r1, r2, r3;
17 r1 = r2 = r3;
18 printf( "%d %d %d\n",
19 r1.depth, r2.depth, r3.depth );
20 }
1 #include "stdio.h"
2 #include "string.h"
3
4 char husband[] = " Charlie";
5 char wife[] = " Sandra";
6
7 char *trim( char *s )
8 { // removing leading blanks
9 char *p = new char[strlen(s)+1];
10 strcpy( p, s );
11 while( *p == ' ' ) p++;
12 strcpy( s, p );
13 delete p;
14 return s;
15 }
16
17 int main()
18 {
19 printf( "...pleased to announce the wedding of"
20 " %s and %s\n", trim(husband), trim(wife) );
21 return 0;
22 }
ANSWERS
1. In line 13, a warning generated for possible access for out of bounds pointer
2. In line 6, a warning is generated for the call of a virtual function 'Animal:init(void)' within a constructor or destructor
3. In line 18, a warning is generated for 'signed-unsigned' mix with divide.
4. In line 11, the assignment operator must return *this
5. In line 13, improper deallocation of the pointer. It should be 'delele []p' instead of 'delete p'
