diff --git a/problems/0017.电话号码的字母组合.md b/problems/0017.电话号码的字母组合.md
index 58508e08..b3bbf122 100644
--- a/problems/0017.电话号码的字母组合.md
+++ b/problems/0017.电话号码的字母组合.md
@@ -503,7 +503,7 @@ func letterCombinations(_ digits: String) -> [String] {
 
     var result = [String]()
     var s = ""
-    func backtracking(digits: [Int], index: Int) {
+    func backtracking(index: Int) {
         // 结束条件：收集结果
         if index == digits.count {
             result.append(s)
@@ -514,11 +514,11 @@ func letterCombinations(_ digits: String) -> [String] {
         let letters = letterMap[digits[index]]
         for letter in letters {
             s.append(letter) // 处理
-            backtracking(digits: digits, index: index + 1) // 递归，记得+1
+            backtracking(index: index + 1) // 递归，记得+1
             s.removeLast() // 回溯
         }
     }
-    backtracking(digits: digits, index: 0)
+    backtracking(index: 0)
     return result
 }
 ```