Q77: Stack content of Pushdown Automata

The following push down automata accepts equal number of a’s and b’s. In the left are the transitions shown and in the right, the equivalent automaton is designed.

Question 78: What will be the stack contents after seeing string abbabbaabbab? (from top to bottom)

1. BB
2. AA
3. BA
4. AB

Solution:

The number of b’s are two more than number of a’s. The correct answer is option 1