For this problem, the tape can start with 0s and 1s scattered anywhere on the tape – they do not have to be contiguous. Any permutation of 0s, 1s and blanks is a possible starting configuration. Create a Turing machine that when started anywhere on the tape will halt if and only if there is a 0 somewhere on the tape (for example if there’s a 0 a million squares to the left or right of the r/w head). You should be able to create test input strings that use the □ character to represent blanks (you can copy-paste that symbol from here – you may need to double click on the input box to be able to paste that character). Your test input strings won’t be able to test with any symbols to the left of the r/w head – you’ll just need to make sure your logic for taking care of both directions is sound.