Here is a sample Max-Heap in Java :
PriorityQueue pq1= new PriorityQueue(10, new Comparator() {
public int compare(Integer x, Integer y) {
if (x < y) return 1;
if (x > y) return -1;
return 0;
}
});
pq1.add(5);
pq1.add(10);
pq1.add(-1);
System.out.println("Peek: "+pq1.peek());
The output will be 10