This program reads a nondeterministic pushdown automaton especified in a JSON file, and receives a word as input, then checks if the word is recognized by the automaton.

{ "pda": [ [states], [input alphabet], [stack alphabet], [transitions], [initial states], [final states] ]}

where each element in [transitions] is:

[origin state, input symbol read, symbol to remove from stack, target state, symbol to insert in stack]

{"pda":[
    ["A", "B"],
    ["0", "1"],
    ["X", "Y"],
    [
        ["A", "0", "#", "A", "X"],
        ["A", "1", "#", "A", "Y"],
        ["A", "#", "#", "B", "#"],
        ["A", "0", "#", "B", "#"],
        ["A", "1", "#", "B", "#"],
        ["B", "0", "X", "B", "#"],
        ["B", "1", "Y", "B", "#"]
    ],
    ["A"],
    ["B"]
    ]}

$ python pda.py palindrome.js 0110
Yes
$ python pda.py palindrome.js 1110
No

This program was written for an assignment of my bachelor's degree in Computer Engineering at CEFET-MG.

@thiagorss: best duo 🍻 @rimsa: professor and inspiration 👨‍🏫