Multi tool use

Using Capital letters and small letters to implement Autocomplete in Java

Design an autocomplete function for IDE. Given the String below, some capital letters and small letters are included in the input. We are asked to implement the autocomplete, and all capital letters must be matched.
ex:

String className {
"GraphView",
"DataGraphView",
"DataController",
"GraphViewController",
"DataScienceView"
}

autocomplete(String className, "Data"); --> {"DataGraphView", "DataController", "DataScienceView"};
autocomplete(String className, "GVi"); --> {"GraphView", "GraphViewController"};
autocomplete(String className, "GraphController"); --> {""};


I think maybe I could use trie, but I don't know how to handle the case2, which is "GVi". Does anyone who could help me on this? Any idea or codes are appreciated! Thanks a lot!

1 Answer
1

That's actually not that difficult, I hope this will help you to think. Don't use too much StackOverflow for homework, or you'll have some trouble during tech interviews later in your life ;)

public static String autocomplete(String classNames, String input) {
String inputAsRegexp = input.replaceAll("([A-Z][a-z]*)", "$1[a-z]*") + ".*";
return Arrays.stream(classNames).filter(className -> className.matches(inputAsRegexp)).toArray(String::new);
}


First line prepare a regexp from the input. It detects an uppercase letter followed by any lowercase letters, then add an unlimited number of lowercase letters to go to the end of the name segment. Then it adds .* to matchs the remaining.

Example: GVi -> G[a-z]*Vi[a-z]*.*

GVi -> G[a-z]*Vi[a-z]*.*

Once I've made this regexp, I just filter the classnames based on it.

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