How many terminal characters appear in the parse tree for 10*4+8?

computer science

Description

Section 1

The following language is ambiguous. Answer questions about how it can interpret expressions.

E -> E + E | E * E | (E) | N
N -> DN | D
D -> 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0

Depending on how the CFG interprets the input, expressions can be evaluated differently.

For example, 2*5+1 could mean 2*(5+1)=12 or (2*5)+1=11. The language is ambiguous, both of these interpretations are correct for this CFG.

Enter all the different result values for the give expression. Separate the numbers with commas. If the above example was give, the answer would be 11,12.

Question 1Enter all possible results from evaluating the expression below. Separate values using commas.

1+5*7+3

Score: 0 out of 10

Question 2Enter all possible results from evaluating the expression below. Separate values using commas.

7*4*9*10

Score: 0 out of 10

Question 3Enter all possible results from evaluating the expression below. Separate values using commas.

2*3+4*5

Score: 0 out of 10

Section 2

In the following section, you will be given 4 CFG and a string. Select all CFG that accpet the input string. Another way to think about it is, select all CFG that can generate the string given.

Question 4Which CFG can accept the string 000111 (Select all that apply)
Score: 7.5 out of 10
 M -> 0M1 | epsilon
 X -> 0X1X | 1X0X | epsilon
 P -> 0P1P | epsilon
 S -> 0S0 | 1S1 | 1 | 0 | epsilon

Question 5Which CFG can accept the string 1001 (Select all that apply)
Score: 2.5 out of 10
 M -> 0M1 | epsilon
 X -> 0X1X | 1X0X | epsilon
 P -> 0P1P | epsilon
 S -> 0S0 | 1S1 | 1 | 0 | epsilon

Question 6Which CFG can accept the string 011100 (Select all that apply)
Score: 0 out of 10
 M -> 0M1 | epsilon
 X -> 0X1X | 1X0X | epsilon
 P -> 0P1P | epsilon
 S -> 0S0 | 1S1 | 1 | 0 | epsilon

Question 7Which CFG can accept the string 1110111 (Select all that apply)
Score: 5 out of 10
 M -> 0M1 | epsilon
 X -> 0X1X | 1X0X | epsilon
 P -> 0P1P | epsilon
 S -> 0S0 | 1S1 | 1 | 0 | epsilon

Section 3

Use the Math Parser to answer these questions.

Question 8How many times does the Number variable appear in the parse tree for 1589?
Score: 0 out of 10

Question 9How many times does the Add variable appear in the parse tree for 1+2+3+(4)?
Score: 10 out of 10

Question 10How many terminal characters appear in the parse tree for 10*4+8?
Score: 0 out of 10

 

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