diff --git a/src/class183/Code01_Ratio1.java b/src/class183/Code01_Ratio1.java
index dca87e2d..ee1cd300 100644
--- a/src/class183/Code01_Ratio1.java
+++ b/src/class183/Code01_Ratio1.java
@@ -25,9 +25,12 @@ public class Code01_Ratio1 {
 	public static int[] weight = new int[MAXN << 1];
 	public static int cntg;
 
+	// vis[u] = true，表示u是之前的分治点
 	public static boolean[] vis = new boolean[MAXN];
 	public static int[] siz = new int[MAXN];
 
+	// cur[v]，表示往下走的当前路径中，路径权值和 % 3 == v的路径有多少条
+	// all[v]，表示往下走的所有路径中，路径权值和 % 3 == v的路径有多少条
 	public static int[] cur = new int[3];
 	public static int[] all = new int[3];
 
@@ -83,7 +86,7 @@ public static void dfs(int u, int fa, int dis) {
 	}
 
 	public static int calc(int u) {
-		int ans = 0;
+		int ans = 1;
 		all[0] = all[1] = all[2] = 0;
 		for (int e = head[u]; e > 0; e = nxt[e]) {
 			int v = to[e];
@@ -101,8 +104,9 @@ public static int calc(int u) {
 	}
 
 	public static int solve(int u) {
+		int ans = 0;
 		vis[u] = true;
-		int ans = calc(u);
+		ans += calc(u);
 		for (int e = head[u]; e > 0; e = nxt[e]) {
 			int v = to[e];
 			if (!vis[v]) {
@@ -123,7 +127,8 @@ public static void main(String[] args) throws Exception {
 			addEdge(u, v, w);
 			addEdge(v, u, w);
 		}
-		int a = solve(getCentroid(1, 0)) + n;
+		int centroid = getCentroid(1, 0);
+		int a = solve(centroid);
 		int b = n * n;
 		int c = gcd(a, b);
 		a /= c;
diff --git a/src/class183/Code01_Ratio2.java b/src/class183/Code01_Ratio2.java
index f3c99fa6..ca8a1375 100644
--- a/src/class183/Code01_Ratio2.java
+++ b/src/class183/Code01_Ratio2.java
@@ -81,7 +81,7 @@
 //}
 //
 //int calc(int u) {
-//    int ans = 0;
+//    int ans = 1;
 //    all[0] = all[1] = all[2] = 0;
 //    for (int e = head[u]; e; e = nxt[e]) {
 //        int v = to[e];
@@ -99,8 +99,9 @@
 //}
 //
 //int solve(int u) {
+//    int ans = 0;
 //    vis[u] = true;
-//    int ans = calc(u);
+//    ans += calc(u);
 //    for (int e = head[u]; e; e = nxt[e]) {
 //        int v = to[e];
 //        if (!vis[v]) {
@@ -119,7 +120,8 @@
 //        addEdge(u, v, w);
 //        addEdge(v, u, w);
 //    }
-//    int a = solve(getCentroid(1, 0)) + n;
+//    int centroid = getCentroid(1, 0);
+//    int a = solve(centroid);
 //    int b = n * n;
 //    int c = gcd(a, b);
 //    a /= c;
diff --git a/src/class183/Code02_Template1.java b/src/class183/Code02_Exist1.java
similarity index 98%
rename from src/class183/Code02_Template1.java
rename to src/class183/Code02_Exist1.java
index d5e855f1..5484d790 100644
--- a/src/class183/Code02_Template1.java
+++ b/src/class183/Code02_Exist1.java
@@ -1,6 +1,6 @@
 package class183;
 
-// 点分治模版题，java版
+// 距离为k的点对是否存在，java版
 // 一共有n个节点，给定n-1条边，每条边有边权，所有节点组成一棵树
 // 一共有m条查询，每条查询给定数字k，打印树上距离为k的点对是否存在
 // 1 <= n <= 10^4    1 <= 边权 <= 10^4
@@ -13,7 +13,7 @@
 import java.io.OutputStreamWriter;
 import java.io.PrintWriter;
 
-public class Code02_Template1 {
+public class Code02_Exist1 {
 
 	public static int MAXN = 10001;
 	public static int MAXM = 101;
diff --git a/src/class183/Code02_Template2.java b/src/class183/Code02_Exist2.java
similarity index 98%
rename from src/class183/Code02_Template2.java
rename to src/class183/Code02_Exist2.java
index 5934f081..3be243bd 100644
--- a/src/class183/Code02_Template2.java
+++ b/src/class183/Code02_Exist2.java
@@ -1,6 +1,6 @@
 package class183;
 
-// 点分治模版题，C++版
+// 距离为k的点对是否存在，C++版
 // 一共有n个节点，给定n-1条边，每条边有边权，所有节点组成一棵树
 // 一共有m条查询，每条查询给定数字k，打印树上距离为k的点对是否存在
 // 1 <= n <= 10^4    1 <= 边权 <= 10^4
diff --git a/src/class183/Code03_Race1.java b/src/class183/Code03_Race1.java
index 6627eaca..72695dc9 100644
--- a/src/class183/Code03_Race1.java
+++ b/src/class183/Code03_Race1.java
@@ -194,9 +194,8 @@ public static int calc(int u) {
 	}
 
 	public static int solve(int u) {
-		int ans = INF;
 		vis[u] = true;
-		ans = Math.min(ans, calc(u));
+		int ans = calc(u);
 		for (int e = head[u]; e > 0; e = nxt[e]) {
 			int v = to[e];
 			if (!vis[v]) {
diff --git a/src/class183/Code03_Race2.java b/src/class183/Code03_Race2.java
index 94318192..d286b37e 100644
--- a/src/class183/Code03_Race2.java
+++ b/src/class183/Code03_Race2.java
@@ -111,9 +111,8 @@
 //}
 //
 //int solve(int u) {
-//    int ans = INF;
 //    vis[u] = true;
-//    ans = min(ans, calc(u));
+//    int ans = calc(u);
 //    for (int e = head[u]; e; e = nxt[e]) {
 //        int v = to[e];
 //        if (!vis[v]) {
diff --git a/src/class183/Code06_Maschera1.java b/src/class183/Code06_Maschera1.java
index 9d0a1ad3..314f0b74 100644
--- a/src/class183/Code06_Maschera1.java
+++ b/src/class183/Code06_Maschera1.java
@@ -40,7 +40,8 @@ public class Code06_Maschera1 {
 
 	// 讲解118，递归函数改成迭代所需要的栈
 	public static int[][] stack = new int[MAXN][5];
-	public static int stacksize, u, f, maxv, edge, e;
+	public static int u, f, maxv, edge, e;
+	public static int stacksize;
 
 	public static void push(int u, int f, int maxv, int edge, int e) {
 		stack[stacksize][0] = u;
diff --git a/src/class183/Code07_Message1.java b/src/class183/Code07_Message1.java
index 9e5f16c1..3a37d281 100644
--- a/src/class183/Code07_Message1.java
+++ b/src/class183/Code07_Message1.java
@@ -45,7 +45,8 @@ public class Code07_Message1 {
 
 	// 讲解118，递归函数改成迭代所需要的栈
 	public static int[][] stack = new int[MAXN][4];
-	public static int stacksize, u, f, dep, e;
+	public static int u, f, dep, e;
+	public static int stacksize;
 
 	public static void push(int u, int f, int dep, int e) {
 		stack[stacksize][0] = u;
diff --git a/src/class184/Code01_Capital1.java b/src/class184/Code01_Capital1.java
index 3b0f8531..5678bebc 100644
--- a/src/class184/Code01_Capital1.java
+++ b/src/class184/Code01_Capital1.java
@@ -42,7 +42,8 @@ public class Code01_Capital1 {
 
 	// 讲解118，递归函数改成迭代所需要的栈
 	public static int[][] stack = new int[MAXN][4];
-	public static int stacksize, u, f, stamp, e;
+	public static int u, f, stamp, e;
+	public static int stacksize;
 
 	public static void push(int u, int f, int stamp, int e) {
 		stack[stacksize][0] = u;