Q1.
Define a function named hasDuplicate that, when passed an ArrayList of Integer objects, returns true if it contains any duplicates (an item occurring more than once), and false otherwise.
For example:
Test
Result
System.out.println(hasDuplicate(new ArrayList<Integer>(Arrays.asList(10, 70, 20, 90))));
false
System.out.println(hasDuplicate(new ArrayList<Integer>(Arrays.asList(10, 70, 20, 90, 20))));
true
System.out.println(hasDuplicate(new ArrayList<Integer>(Arrays.asList(10, 70, 20, 90, 90))));
true
System.out.println(hasDuplicate(new ArrayList<Integer>(Arrays.asList(10, 70, 20, 90, 10))));
true
ArrayList<Integer> list = new ArrayList<Integer>();
for (int i = 0; i < 1000; i++) {
list.add(i);
}
false
true
System.out.println(hasDuplicate(list));
list.set(50, 99);
System.out.println(hasDuplicate(list));