Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision 		Previous revision
aa:lab:03 [2020/10/21 13:36]
pdmatei 		aa:lab:03 [2020/10/23 14:43] (current)
pdmatei
Line 9: Line 9:
 ==== 1. Accepting and deciding a decision problem ==== ==== 1. Accepting and deciding a decision problem ====
  
-**1.1** Can the problem $math[f(w) = 0] (for all w in Sigma*) be accepted by a Turing Machine?+**1.1** Can the problem $math[f(w) = 0] (for all w in $math[\Sigma^*]) be accepted by a Turing Machine?
  
 **1.2** Can a problem be accepted by two different Turing Machines? **1.2** Can a problem be accepted by two different Turing Machines?
Line 15: Line 15:
 **1.3** Can a Turing Machine accept two different problems? **1.3** Can a Turing Machine accept two different problems?
  
-**1.4** Write a Turing Machine which accepts the problem $math[f(x) = 1] iff x (as binary) is odd, but does **NOT** decide it.+**1.4** Write a Turing Machine which accepts the problem $math[f(x) = 1] iff x (encoded ​as binary ​word) is odd, but does **NOT** decide it.
  
 **1.5** ​ Which of the following problems you think can be accepted and which can be decided? Use pseudocode instead of writing a TM. **1.5** ​ Which of the following problems you think can be accepted and which can be decided? Use pseudocode instead of writing a TM.
Line 46: Line 46:
 ==== 2. Complement ==== ==== 2. Complement ====
  
-**2.1** What is the complement of the previous ​problem?+**2.1** What is the complement of the problem ​from Exercise 1.1 ?
  
 **2.2** What is the complement of k Vertex Cover? **2.2** What is the complement of k Vertex Cover?
Line 52: Line 52:
 **2.3** If a problem is decided by some TM, can its complement be decided? **2.3** If a problem is decided by some TM, can its complement be decided?
  
-**2.4** If a problem is accepted by some TM, can its complement be decided?+**2.4** If a problem is accepted by some TM, can its complement be accepted?
  
 ==== 3. Turing Machine pseudocode ==== ==== 3. Turing Machine pseudocode ====
Line 62: Line 62:
 Suppose M is encoded on binary words, and also working on binary words, for simplicity. Suppose M is encoded on binary words, and also working on binary words, for simplicity.
  
 +/* Solution:
 <​code>​ <​code>​
 Pseudocode(M):​ <- input Pseudocode(M):​ <- input
Line 74: Line 75:
         repeat the same process all over         repeat the same process all over
 </​code>​ </​code>​
 +
 +*/
  
 **3.2** Which of the following pseudocode is a proper Turing Machine? Explain why. **3.2** Which of the following pseudocode is a proper Turing Machine? Explain why.