diff --git a/408/数据结构/6 树和二叉树/6 树和二叉树.md b/408/数据结构/6 树和二叉树/6 树和二叉树.md
index e708215..4cd0848 100644
--- a/408/数据结构/6 树和二叉树/6 树和二叉树.md	
+++ b/408/数据结构/6 树和二叉树/6 树和二叉树.md	
@@ -42,22 +42,7 @@
 
 ### 6.1① 已知一棵树边的集合为 $\{ <I, M>, <I, N>, <E, I>, <B, E>, <B, D>, <A, B>, <G, J>, <G, K>, <C, G>, <C, F>, <H, L>, <C, H>, <A, C> \}$，请画出这棵树，并回答下列问题：
 
-```mermaid
-graph TB
-A --- B
-A --- C
-B --- D
-B --- E
-C --- F
-C --- G
-C --- H
-E --- I
-G --- J
-G --- K
-H --- L
-I --- M
-I --- N
-```
+<img src="assets/6.19.png">
 
 #### （1）哪个是根结点？
 
@@ -158,8 +143,8 @@ $$
 | :-------------: | :---------------: | :---------------: | :---------------: |
 | $n$ 在 $m$ 左方 |         1         |         1         |         1         |
 | $n$ 在 $m$ 右方 |         0         |         0         |         0         |
-| $n$ 是 $m$ 祖先 |         1         |         φ         |         φ         |
-| $n$ 是 $m$ 子孙 |         1         |         φ         |         φ         |
+| $n$ 是 $m$ 祖先 |         1         |         φ         |         0         |
+| $n$ 是 $m$ 子孙 |         0         |         φ         |         1         |
 
 > 注：如果 ① 离 a 和 b 最近的共同祖先 p 存在，且 ② a 在 p 的左子树中，b 在 p 的右子树中，则称 a 在 b 的左方（即 b 在 a 的右方）。
 
@@ -167,10 +152,7 @@ $$
 
 #### （a）它们在先序遍历和中序遍历时，得到的结点访问序列相同；
 
-```mermaid
-graph TB
-1(1)
-```
+<img src="assets/6.14.a.png">
 
 #### （b）它们在后序遍历和中序遍历时，得到的结点访问序列相同；
 
diff --git a/408/数据结构/6 树和二叉树/assets/6.14.a.dot b/408/数据结构/6 树和二叉树/assets/6.14.a.dot
new file mode 100644
index 0000000..2ba554a
--- /dev/null
+++ b/408/数据结构/6 树和二叉树/assets/6.14.a.dot	
@@ -0,0 +1,11 @@
+graph a {
+    splines="FALSE";
+
+    /* Entities */
+    1[shape = circle]
+    
+    /* Relationships */
+    1
+
+    /* Ranks */
+}
\ No newline at end of file
diff --git a/408/数据结构/6 树和二叉树/assets/6.14.a.png b/408/数据结构/6 树和二叉树/assets/6.14.a.png
new file mode 100644
index 0000000..e1abcb1
Binary files /dev/null and b/408/数据结构/6 树和二叉树/assets/6.14.a.png differ
diff --git a/408/数据结构/6 树和二叉树/assets/6.19.dot b/408/数据结构/6 树和二叉树/assets/6.19.dot
new file mode 100644
index 0000000..a207226
--- /dev/null
+++ b/408/数据结构/6 树和二叉树/assets/6.19.dot	
@@ -0,0 +1,36 @@
+graph 6.19 {
+    splines="FALSE";
+
+    /* Entities */
+    A [shape = circle]
+    B [shape = circle]
+    C [shape = circle]
+    D [shape = circle]
+    E [shape = circle]
+    F [shape = circle]
+    G [shape = circle]
+    H [shape = circle]
+    I [shape = circle]
+    J [shape = circle]
+    K [shape = circle]
+    L [shape = circle]
+    M [shape = circle]
+    N [shape = circle]
+    
+    /* Relationships */
+    A -- B
+    A -- C
+    B -- D
+    B -- E
+    C -- F
+    C -- G
+    C -- H
+    E -- I
+    G -- J
+    G -- K
+    H -- L
+    I -- M
+    I -- N
+
+    /* Ranks */
+}
\ No newline at end of file
diff --git a/408/数据结构/6 树和二叉树/assets/6.19.png b/408/数据结构/6 树和二叉树/assets/6.19.png
new file mode 100644
index 0000000..9a49715
Binary files /dev/null and b/408/数据结构/6 树和二叉树/assets/6.19.png differ
diff --git a/408/数据结构/6 树和二叉树/assets/6.3.dot b/408/数据结构/6 树和二叉树/assets/6.3.dot
new file mode 100644
index 0000000..a9e1d1e
--- /dev/null
+++ b/408/数据结构/6 树和二叉树/assets/6.3.dot	
@@ -0,0 +1,29 @@
+graph 6.3 {
+    subgraph A {
+        subgraph Aa{
+            Aa1[label = "", shape = circle]
+            Aa2[label = "", shape = circle]
+            Aa3[label = "", shape = circle]
+
+            Aa1--Aa2--Aa3
+        }
+        subgraph Ab{
+            Ab1[label = "", shape = circle]
+            Ab2[label = "", shape = circle]
+            Ab3[label = "", shape = circle]
+            
+            Ab1--Ab2
+            Ab1--Ab3
+        }
+    }
+    subgraph B {
+        subgraph Ba{
+            Ba1[label = "", shape = circle]
+            Ba1[label = "", shape = circle]
+            Ba2[label = "", shape = circle]
+            Ba3[label = "", shape = circle]
+
+            Ba1--Ba2--Ba3
+        }
+    }
+}
\ No newline at end of file