Chapter 9 Exercise Set 1: CPE Practice

1. What is the output of the following program?

   #include <iostream>
   using namespace std;
   
   int main() {
       int a[6];
       for (int i = 0; i < 6; i++)
           a[i] = 2 * i + 4;
       cout << a[4] / a[1] << endl;
   
       return 0;
   }
   

2. What is the output of the following program?

   #include <iostream>
   using namespace std;
   
   int main() {
       int a = 2, b = 3;
       if (a > b && b > a)
           a++;
       if (a > b || b > a)
           b++;
       if (a | b)
           a++;
       if (a & b)
           b++;
       cout << a * b << endl;
   
       return 0;
   }
   

3. What is the output of the following program?

   #include <iostream>
   using namespace std;
   
   int main() {
       int a = 1, b = 2, c;
       a = a << b;
       b = b << a;
       c = b >> a;
       cout << c << endl;
   
       return 0;
   }
   

4. What is the output of the following program?

   #include <iostream>
   using namespace std;
   
   int main() {
       float a[3][3] = {{.1, 1., 10.}, {10., .1, 1.}, {.1, 10., 1.}};
       float f = 10.;
       for (int i = 0; i < 3; i++)
           f *= a[i][i];
       cout << f << endl;
   
       return 0;
   }
   

5. What is the output of the following program?

   #include <iostream>
   using namespace std;
   
   int main() {
     int nums[4] = {16, 8, 4, 2};
     int *p1 = nums + 2, *p2 = p1 - 1;
     p1++;
     cout << *p1 << ' ' << *p2 << ' ' << p1 - p2 << ' ';
     cout << *p1 + nums[p1 - p2] << endl;
   
     return 0;
   }
   

6. What is the output of the following program?

   #include <iostream>
   using namespace std;
   
   void swap(int n, int m) {
       int t = n;
       n = m;
       m = t;
   } 
   
   void swap(int* ip1, int* ip2) {
       int t = *ip1;
       *ip1 = *ip2;
       *ip2 = t;
   } 
   
   int main() {
       int x = 7, y = 11;
       swap(x, y);
       cout << x << ' ' << y << ' ';
       swap(&x, &y);
       cout << x << ' ' << y << endl;
       return 0;
   }
   

7. What is the output of the following program?

   #include <iostream>
   using namespace std;
   
   int main() {
       int i = 0;
       for (float f = .008; f < 1e2; f *= 1e1)
           i++;
       cout << i << endl;
       return 0;
   }
   

8. What is the output of the following program?

   #include <iostream>
   using namespace std;
   
   char f1(char *p) {
       return ++(*p);
   }
   
   char *f2(char *p) {
       char c = *p - 3;
       *p = c;
       return p;
   }
   
   char *f3(char &n) {
       return &--n;
   }
   
   int main() {
       char mystery = 'z';
       cout << f1(f2(f3(mystery))) << endl;
       return 0;
   }
   

9. What is the output of the following program?

   #include <iostream>
   using namespace std;
   
   int main() {
       int *ip[2] = {new int[2], new int[2]};
       for (int i = 0; i < 4; i++)
           ip[i % 2][i / 2] = i * 3;
       cout << ip[0][0] << ' ' << ip[0][1] << ' ';
       cout << ip[1][0] << ' ' << ip[1][1] << endl;
       delete[] ip[0];
       delete[] ip[1];
   
     return 0;
   }
   

10. What is the output of the following program?

    #include <iostream>
    using namespace std;
    
    int main() {
        int *ia[3] = { new int[3], new int[3], new int[3] }, *ip;
    
        for (int i = 0; i < 3; i++) {
            ip = ia[i];
            *ip = ip[1] = *(ip + 2) = i + 5;
        }
        cout << ia[0][0] << ' ' << ia[0][1] << ' ' << ia[0][2] << ' '; 
        cout << ia[1][0] << ' ' << ia[1][1] << ' ' << ia[1][2] << ' '; 
        cout << ia[2][0] << ' ' << ia[2][1] << ' ' << ia[2][2] << endl; 
        delete[] ia[0];
        delete[] ia[1];
        delete[] ia[2];
        return 0;
    }
    

11. What is the output of the following program?

    #include <iostream>
    using namespace std;
    
    int main() {
        int* ia[3];
    
        for (int i = 0; i < 3; i++) {
            ia[i] = new int[i + 1];
            for (int j = 0; j < i + 1; j++)
                ia[i][j] = 10 * i + j + 2;
        }
        cout << ia[0][0] << endl;
        cout << ia[1][0] << ' ' << ia[1][1] << endl;
        cout << ia[2][0] << ' ' << ia[2][1] << ' ' << ia[2][2] << endl; 
        for (int i = 0; i < 3; i++)
            delete[] ia[i];
        return 0;
    }