diff --git a/notes/49. 丑数.md b/notes/49. 丑数.md
index f92d4d12..f2aa4566 100644
--- a/notes/49. 丑数.md	
+++ b/notes/49. 丑数.md	
@@ -1,6 +1,6 @@
 # 49. 丑数
 
-[NowCoder](https://www.nowcoder.com/practice/6aa9e04fc3794f68acf8778237ba065b?tpId=13&tqId=11186&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking&from=cyc_github)
+[Leetcode](https://leetcode.cn/problems/chou-shu-lcof/)
 
 ## 题目描述
 
@@ -9,13 +9,13 @@
 ## 解题思路
 
 ```java
-public int GetUglyNumber_Solution(int N) {
-    if (N <= 6)
-        return N;
+public int nthUglyNumber(int n) {
+    if (n <= 6)
+        return n;
     int i2 = 0, i3 = 0, i5 = 0;
-    int[] dp = new int[N];
+    int[] dp = new int[n];
     dp[0] = 1;
-    for (int i = 1; i < N; i++) {
+    for (int i = 1; i < n; i++) {
         int next2 = dp[i2] * 2, next3 = dp[i3] * 3, next5 = dp[i5] * 5;
         dp[i] = Math.min(next2, Math.min(next3, next5));
         if (dp[i] == next2)
@@ -25,6 +25,6 @@ public int GetUglyNumber_Solution(int N) {
         if (dp[i] == next5)
             i5++;
     }
-    return dp[N - 1];
+    return dp[n - 1];
 }
 ```