diff --git a/src/class05/Code01_TrieTree.java b/src/class05_08/Code01_TrieTree.java
similarity index 99%
rename from src/class05/Code01_TrieTree.java
rename to src/class05_08/Code01_TrieTree.java
index fddcf13..b65b641 100644
--- a/src/class05/Code01_TrieTree.java
+++ b/src/class05_08/Code01_TrieTree.java
@@ -1,10 +1,11 @@
-package class05;
+package class05_08;
 
 import java.util.HashMap;
 
 // 该程序的对数器跑不过，你能发现bug在哪吗？
 public class Code01_TrieTree {
 
+	// 前缀树节点类型
 	public static class Node1 {
 		public int pass;
 		public int end;
diff --git a/src/class05/Code02_TrieTree.java b/src/class05_08/Code02_TrieTree.java
similarity index 99%
rename from src/class05/Code02_TrieTree.java
rename to src/class05_08/Code02_TrieTree.java
index a96cc5f..3de857c 100644
--- a/src/class05/Code02_TrieTree.java
+++ b/src/class05_08/Code02_TrieTree.java
@@ -1,4 +1,4 @@
-package class05;
+package class05_08;
 
 import java.util.HashMap;
 
@@ -10,6 +10,7 @@ public class Code02_TrieTree {
 		public int end;
 		public Node1[] nexts;
 
+		// char tmp = 'b'  (tmp - 'a')
 		public Node1() {
 			pass = 0;
 			end = 0;
diff --git a/src/class05/Code03_CountSort.java b/src/class05_08/Code03_CountSort.java
similarity index 99%
rename from src/class05/Code03_CountSort.java
rename to src/class05_08/Code03_CountSort.java
index 0f64d1c..2a7efb9 100644
--- a/src/class05/Code03_CountSort.java
+++ b/src/class05_08/Code03_CountSort.java
@@ -1,4 +1,4 @@
-package class05;
+package class05_08;
 
 import java.util.Arrays;
 
diff --git a/src/class05/Code04_RadixSort.java b/src/class05_08/Code04_RadixSort.java
similarity index 97%
rename from src/class05/Code04_RadixSort.java
rename to src/class05_08/Code04_RadixSort.java
index 325d97b..7a131ad 100644
--- a/src/class05/Code04_RadixSort.java
+++ b/src/class05_08/Code04_RadixSort.java
@@ -1,4 +1,4 @@
-package class05;
+package class05_08;
 
 import java.util.Arrays;
 
@@ -25,8 +25,7 @@ public class Code04_RadixSort {
 		return res;
 	}
 
-	// arr[l..r]排序  ,  digit
-	// l..r    3 56 17 100    3
+	// arr[L..R]排序  ,  最大值的十进制位数digit
 	public static void radixSort(int[] arr, int L, int R, int digit) {
 		final int radix = 10;
 		int i = 0, j = 0;
@@ -57,10 +56,6 @@ public class Code04_RadixSort {
 				arr[i] = help[j];
 			}
 		}
-		
-		
-		
-		
 	}
 
 	public static int getDigit(int x, int d) {