Name: ____________________________________________________ Alpha: _____________ Section: ________

Describe help received: _________________________________________________________________

See the bottom for how to submit your work.

Due: Before 0800 on next class day

  1. (10 pts) Read today's lecture notes. Honestly declare how you read the notes.
    1. (10 pts) I read the notes carefully. I have a good understanding of the topics therein.
    2. (10 pts) I read the notes carefully, but I don't really understand the following points well:
    3. (0 pts) I didn't read the notes carefully.
  2. [10pts] Suppose we want to read an array size from user, but worry about the user entering 0 or a negative number. Consider the three code snippets below and answer the questions below them. 
    
int n;
cin >> n;
double* Z;
Z = new double[n];
if (n <= 0) {
  cout << "Error!" << endl;
  Z = new double[10];
}

Z[0] = 5;

    
int n;
cin >> n;
if (n <= 0){
  cout << "Error!" << endl;
  double* Z = new double[10];
}
else
  double* Z = new double[n];

Z[0] = 5;

    
int n;
cin >> n;
double* Z;
if (n <= 0){
  cout << "Error!" << endl;
  Z = new double[10];
}
else
  Z = new double[n];

Z[0] = 5;
    circle one:
    • compile-time error
    • possible run-time error
    • OK
    If error, why?     		circle one:
    • compile-time error
    • possible run-time error
    • OK
    If error, why?     		circle one:
    • compile-time error
    • possible run-time error
    • OK
    If error, why?
  3. [10pts] The program toy.cpp listed below is intended to work as follows: For example, given the following input from the terminal 
      5 
  1.1 -1.3 4 -7.4 -3.6
    ... the program should output the following: 
      Negatives in reverse:
  -3.6
  -7.4 
  -1.3
    However, the program doesn't work as it is intended to. Fix the bugs by annotating in the code directly. (Hint: There are 6 bugs).

    Note: A similar question will appear in the exam. Try to solve the problem by hand (and then double-check your answer by compiling and running your solution). 

    
// fix the bugs!!
 1 #include <iostream>
 2 using namespace std;
 3
 4 void print_negatives(double* A, int N);
 5
 6 int main()
 7 {
 8   int N=0;
 9   double* A = new double[N];
10   cin >> N;
11
12   for(int i=0; i<N; i++)
13     cin >> A[N];
14
15   cout << "Negatives in reverse:" << endl;
16
17   void print_negatives(double* A, int N);
18
19   delete [] A;
20
21   return 0;
22 }
23
24 void print_negatives(int* A, int N)
25 {
26   for(int i = N; i >= 0; i--)
27     cout << A[i] << endl;
28 }
Bring to class