For some reason in the trickytest it is supposed to return "??", but I am returning "snake" and there is no way to find out what the mistake is since I can't figure out how it would return a value when "snake" apparently should not be in the string, but it is somehow seeing it in the string. There is that problem and then the other says expected answer mo[o]se, but am getting mo[u]se or expected []cat, but getting [bob]cat. Not sure if I can message my code as I am pretty new to this site and am still pretty new to coding. Thanks for any help!

looks like you get a multidimensional array, i.e. int[][] arr = {{5,0},{8,3},{3,5},{2,1}};
first int indcates people getting on bus, second int indicates people getting off bus. You can probably just do a for loop that adds all of the first
integers and subtracts all of the second integers, should return just an int value of the remaining number of people on the bus.