/ * * * Delete and return the largest key on the priority queue. * Throw an exception if the priority queue is empty. * / public Integer delMax( ) { if (size( ) == 0) { throw new RuntimeException( "Priority queue is empty" ) ; } Integer max = root. data; if (size = = 1) { root = null; size--; return max; private void printHeap(Node n) { if(n == null) return ; System. out. print (n. value+" ") ; printHeap (n. 1child) ; printHeap (n. rchild) ;| private void showHeap( ) { printHeap (root); System. out . printIn( ) ; public static void main (String args) { PtrHeap pq = new PtrHeap( ) ; pq. insert(10) ; pq . insert(20) ; pq . insert(30) ; pq . insert(40) ; pq . insert(50) ; int x = pq. delMax( ) ; // should be 50