Sorting

AP Computer Science A· difficulty 3/5

public class Item implements Comparable<Item> {
    private int v;
    public Item(int x) { v = x; }
    public int compareTo(Item o) { return v - o.v; }
    public int getV() { return v; }
}
// Usage (assume sort puts smallest first):
ArrayList<Item> list = new ArrayList<Item>();
list.add(new Item(3));
list.add(new Item(1));
list.add(new Item(2));
// After Collections.sort(list):
// Print first element's value:

What value is at index 0 after sorting?

A
$3$
B
$1$
check_circle
C
$2$
D
$Sorting fails$

Explanation

Collections.sort uses compareTo. With compareTo returning v - o.v, the natural order is ascending. The smallest value (1) ends up at index 0.

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