1 /** 2 public class TreeNode { 3     int val = 0; 4     TreeNode left = null; 5     TreeNode right = null; 6  7     public TreeNode(int val) { 8         this.val = val; 9 10     }11 12 }13 */14 public class Solution {15     public boolean HasSubtree(TreeNode root1,TreeNode root2) {16 17          boolean result = false;18          19          if(root1 != null && root2 != null){20              21              if(root1.val == root2.val){22                  result = DoesTree1HasTree2(root1,root2);23              }24              25             //递归遍历左子树 26             if(!result){27                 result = HasSubtree(root1.left, root2);28             }29             30             //递归遍历右子树31             if(!result){32                 result = HasSubtree(root1.right, root2);33             }34          }35         36         return result;37     38     }39     40     41     public boolean DoesTree1HasTree2(TreeNode root1,TreeNode root2){42         43         if(root2 == null){44             return true;45         }46         47         if(root1 == null){48             return false;49         }50         51         if(root1.val != root2.val){52             return false;53         }54         55         return DoesTree1HasTree2(root1.left, root2.left) && DoesTree1HasTree2(root1.right, root2.right);56     }57 }