不断递归的实现！！！！ 

下面是AC代码：

1 /** 2      * Given inorder and postorder traversal of a tree, construct the binary tree. 3      * @param inorder 4      * @param postorder 5      * @return 6      */ 7     public TreeNode buildTree(int[] inorder,int[] postorder){ 8         if(inorder == null || postorder ==null  9                 || inorder.length == 0 || postorder.length == 0)10             return null;11         if(inorder.length!=postorder.length)12             return null;13         if(inorder.length == 1)14         {15             if(inorder[0] != postorder[0])16                 return null;17             else18                 return new TreeNode(inorder[0]);19         }20         // make sure how many nodes in the left21         int i=0;22         while(inorder[i++] != postorder[postorder.length-1]);23         int[] leftInorder = new int[i-1];24         int[] leftPostorder = new int[i-1];25         int j = 0;26         while(j