OA exam

Question 1

a hashset contains….
a hashmap contains…
a treemap contains…

Answer 1

hashset. contains(item) –> O(1) (because under is hashmap)
hashmap. containsKey(key) –>O(1)
treemap. containsKey(key) –>O(nlogn)

Question 2

sort a String str characters

Answer 2

char[] charArray = str.toCharArray();
Arrays.sort(charArray);
sortedStr = new String(charArray);

note: char charArray[] is also valid