engineering recuitment GATE CSE 2023-24 Test Series Theory of Computation Context Free Languages and Pushdown Automata Context Free Languages
Which one of the following languages over Σ = {a, b} is/are context-free?
1
{wwR |w ϵ {a, b}*}
2
{wanbnwR |w ϵ {a, b}*, n ≥ 0}
3
{wanwRbn|w ϵ {a, b}*, n ≥ 0}
4
{anbi |i ϵ {n, 3n, 5n}, n ≥ 0}