Customizing Problets

Each problet comes with a repository of over 200 problem templates, each template indexed by one or more learning objectives. Adopters can provide custom problem templates for inclusion in problets. Such templates must be specified in BNF-like notation.

BNF-like Notation:

The notation uses the following non-terminals:

T for data type, e.g., <T1>, <T2>. Note that <T0> is reserved for the data type void
F for function name, e.g., <F1>, <F2>. Note that <F0> is reserved for the function main
V for variable names, e.g., <V1>, <V2>.
P for pointer names, e.g., <P1>, <P2>.
R for random constants, e.g., <R1>, <R2>. Constraints can be specified for the values of the random constants as follows:
- Constant R1 in the range 1 through 5: <R1#1<=R1<=5;#>
- Constant R2 is twice the constant R1: <R2#R2=R1*2;#>
C for class name, e.g., <C1>, <C2>.

The notation uses the following terminals:

if, else for if-else statements
while, do, for for loops
[] for array subscripts, {} for compound statements, blocks, functions, and programs
<< is used as the prefix for print statements

Types of Problems:

Currently, the following types of problems are supported by problets. For each, a sample problem template and the corresponding problem are listed:

Evaluating expressions

Problem template:

      <R1#float;2<=R1<=5;#> % <R2#integer;6<=R2<=9;#>

Corresponding problem presented to the student:
```
      2.5 % 6
     
```

Debugging programs

Problem template:

{<T0><F0>(){<T1#integer#><P1>;<T1><V1>=<R1#1<=R1<=9;#>;{<T1><V2>=<R2#10<=R2<=19;#>;<P1>=
& <V2>;}<<<V1>;<<<P1>;}}

Corresponding problem presented to the student:

void main()
{
   int * pointer;
   int number = 5;
   {
      int count = 13;
      pointer = & count;
   }
   cout << number;
   cout << * pointer;
}

Predicting the output of programs

Problem template:

{<T0><F0>(){<T1#integer#><V1>;for(<V1> =
<R1#1<=R1<=5;#>;<V1> < <R2#integer;6<=R2<=9;#>;<V1> =
<V1> + 1){<<<V1>;}}}

Corresponding problem presented to the student:

void main()
{
   int count;
   for( count = 2; count < 7; count = count + 1 )
   {
      cout << count;
   }
}

Identifying the state of variables in programs (under development)
Filling out missing parts of a program (under development)