I try to construct a TM that accepts the language $\{ ww \mid w \in \{a,b\}^* \}$.Between the words $w$ is no delimeter, so I don't know, how my TM can know where the first $w$ ends and the second $w$ begins. Is there a trick for this?
Construct Turing Machine which accepts the language $ww$
formal languages;turing machines;automata
Here is a sketch for how a deterministic machine might work:place a marker in front of the input.go through the input, checking if the length is even. If not, reject.place a marker behind the input.going back and forth, move the markers towards each other until they meet in the middle.as long as the halves are nonempty, compare and erase their first letters and reject if not equal.accept.