public class binarytrees { public static void main(String[] args){ final int minDepth = 4; int n = (args.length > 0) ? Integer.parseInt(args[0]) : 3; int maxDepth = (minDepth + 2 > n) ? minDepth + 2 : n; int stretchDepth = maxDepth + 1; int check = (TreeNode.bottomUpTree(0,stretchDepth)).itemCheck(); System.out.println("stretch tree of depth "+stretchDepth+"\t check: " + check); TreeNode longLivedTree = TreeNode.bottomUpTree(0,maxDepth); for (int depth=minDepth; depth<=maxDepth; depth+=2){ int iterations = 1 << (maxDepth - depth + minDepth); check = 0; for (int i=1; i<=iterations; i++){ check += (TreeNode.bottomUpTree(i,depth)).itemCheck(); check += (TreeNode.bottomUpTree(-i,depth)).itemCheck(); } System.out.println((iterations*2) + "\t trees of depth " + depth + "\t check: " + check); } System.out.println("long lived tree of depth " + maxDepth + "\t check: "+ longLivedTree.itemCheck()); } private static class TreeNode { private TreeNode left, right; private int item; TreeNode(int item){ this.item = item; } private static TreeNode bottomUpTree(int item, int depth){ if (depth>0){ return new TreeNode( bottomUpTree(2*item-1, depth-1) , bottomUpTree(2*item, depth-1) , item ); } else { return new TreeNode(item); } } TreeNode(TreeNode left, TreeNode right, int item){ this.left = left; this.right = right; this.item = item; } private int itemCheck(){ // if necessary deallocate here if (left==null) return item; else return item + left.itemCheck() - right.itemCheck(); } } }