// 前序遍歷序列{1,2,4,7,3,5,6,8}和中序遍歷序列{4,7,2,1,5,3,8,6}
		public TreeNode reConstructBinaryTree(int[] pre, int[] in)
			{
				if (pre == null || in == null || pre.length != in.length)
					return null;
				TreeNode pHeadNode = new TreeNode(pre[0]);
				int i = 0;
				for (i = 0; i < in.length; i++)
					if (pre[0] == in[i])
						break;
				pHeadNode.left = reConstructBinaryTree(pre, in, 1, 0, i - 1);
				pHeadNode.right = reConstructBinaryTree(pre, in, i + 1, i + 1,
						in.length - 1);
				return pHeadNode;
			}
		/**
		 * @param pre 前序遍歷的陣列
		 * @param in	中序遍歷的陣列
		 * @param mid  根節點的值
		 * @param start 子樹的開始節點
		 * @param end 子樹的開始節點
		 * @return
		 */
		public TreeNode reConstructBinaryTree(int[] pre, int[] in, int mid,
				int start, int end)
			{
				if (end < start)
					return null;
				TreeNode node = new TreeNode(pre[mid]);
				if (end == start)
					return node;
				int i = 0;
				for (i = start; i <= end; i++)
					if (pre[mid] == in[i])
						break;
				if (i == start)
					node.left = null;
				else
					node.left = reConstructBinaryTree(pre, in, mid + 1, start,
							i - 1);
				if (i == end)
					node.right = null;
				else
					node.right = reConstructBinaryTree(pre, in, mid + 1 + i
							- start, i + 1, end);
				return node;
			}