class Solution {

     public boolean isSame(TreeNode r1,TreeNode r2)
     {
         if(r2==null)//r2为空，不论r1是否为空
             return true;
         else if(r1==null)
             return false;
         else if(r1.val!=r2.val)//二者均不为空且值不想等
             return false;
         else
             return isSame(r1.left,r2.left) && isSame(r1.right,r2.right);
     }
    //依次遍历整棵树
     public boolean hasSubtree(TreeNode pRoot1, TreeNode pRoot2) {
         if(pRoot1==null||pRoot2==null)
             return false;

         if(isSame(pRoot1,pRoot2))
             return true;

         return hasSubtree(pRoot1.right,pRoot2)||hasSubtree(pRoot1.left,pRoot2);
     }

}