转换平衡二叉树

只是近似。

/**
 * 一个整数数组，近似转换成一颗平衡二叉树。
 * 先排序，然后选取中位数，先序遍历
 *
 */
public class BalanceTree {

	public static Node balance(int[] a, int left, int right){
		if(left == right){
			return new Node(a[left]);
		}
		if(left > right){
			return null;
		}
		int p = (left+right)/2;
		Node parent = new Node(a[p]);
		Node leftChild = balance(a, left, p-1);
		Node rightChild = balance(a, p+1, right);
		parent.left = leftChild;
		parent.right = rightChild;
		return parent;
	}
	
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		int[] a = {1,2,3,4,5,6,7,8,9};
		Node root = BalanceTree.balance(a, 0, a.length-1);
		BFS.bfs(root);
	}

}