diff --git a/solution/0600-0699/0680.Valid Palindrome II/README.md b/solution/0600-0699/0680.Valid Palindrome II/README.md
index b651d09244914..8d0a6481253af 100644
--- a/solution/0600-0699/0680.Valid Palindrome II/README.md	
+++ b/solution/0600-0699/0680.Valid Palindrome II/README.md	
@@ -94,18 +94,21 @@ class Solution:
 
 ```java
 class Solution {
-    public boolean validPalindrome(String s) {
-        for (int i = 0, j = s.length() - 1; i < j; ++i, --j) {
-            if (s.charAt(i) != s.charAt(j)) {
-                return check(s, i + 1, j) || check(s, i, j - 1);
+    private char[] s;
+
+    public boolean validPalindrome(String S) {
+        this.s = S.toCharArray();
+        for (int i = 0, j = s.length - 1; i < j; ++i, --j) {
+            if (s[i] != s[j]) {
+                return check(i + 1, j) || check(i, j - 1);
             }
         }
         return true;
     }
 
-    private boolean check(String s, int i, int j) {
+    private boolean check(int i, int j) {
         for (; i < j; ++i, --j) {
-            if (s.charAt(i) != s.charAt(j)) {
+            if (s[i] != s[j]) {
                 return false;
             }
         }
@@ -120,18 +123,17 @@ class Solution {
 class Solution {
 public:
     bool validPalindrome(string s) {
-        for (int i = 0, j = s.size() - 1; i < j; ++i, --j) {
-            if (s[i] != s[j]) {
-                return check(s, i + 1, j) || check(s, i, j - 1);
+        auto check = [&](int i, int j) {
+            for (; i < j; ++i, --j) {
+                if (s[i] != s[j]) {
+                    return false;
+                }
             }
-        }
-        return 1;
-    }
-
-    bool check(string s, int i, int j) {
-        for (; i < j; ++i, --j) {
+            return true;
+        };
+        for (int i = 0, j = s.size() - 1; i < j; ++i, --j) {
             if (s[i] != s[j]) {
-                return false;
+                return check(i + 1, j) || check(i, j - 1);
             }
         }
         return true;
@@ -164,18 +166,17 @@ func validPalindrome(s string) bool {
 
 ```ts
 function validPalindrome(s: string): boolean {
-    for (let i: number = 0, j = s.length - 1; i < j; ++i, --j) {
-        if (s.charAt(i) != s.charAt(j)) {
-            return isPalinddrome(s.slice(i, j)) || isPalinddrome(s.slice(i + 1, j + 1));
+    const check = (i: number, j: number): boolean => {
+        for (; i < j; ++i, --j) {
+            if (s[i] !== s[j]) {
+                return false;
+            }
         }
-    }
-    return true;
-}
-
-function isPalinddrome(s: string): boolean {
-    for (let i: number = 0, j = s.length - 1; i < j; ++i, --j) {
-        if (s.charAt(i) != s.charAt(j)) {
-            return false;
+        return true;
+    };
+    for (let i = 0, j = s.length - 1; i < j; ++i, --j) {
+        if (s[i] !== s[j]) {
+            return check(i + 1, j) || check(i, j - 1);
         }
     }
     return true;
@@ -190,16 +191,16 @@ function isPalinddrome(s: string): boolean {
  * @return {boolean}
  */
 var validPalindrome = function (s) {
-    let check = function (i, j) {
+    const check = function (i, j) {
         for (; i < j; ++i, --j) {
-            if (s.charAt(i) != s.charAt(j)) {
+            if (s[i] !== s[j]) {
                 return false;
             }
         }
         return true;
     };
     for (let i = 0, j = s.length - 1; i < j; ++i, --j) {
-        if (s.charAt(i) != s.charAt(j)) {
+        if (s[i] !== s[j]) {
             return check(i + 1, j) || check(i, j - 1);
         }
     }
diff --git a/solution/0600-0699/0680.Valid Palindrome II/README_EN.md b/solution/0600-0699/0680.Valid Palindrome II/README_EN.md
index 81e3c902dc8f9..6826d68fbe174 100644
--- a/solution/0600-0699/0680.Valid Palindrome II/README_EN.md	
+++ b/solution/0600-0699/0680.Valid Palindrome II/README_EN.md	
@@ -91,18 +91,21 @@ class Solution:
 
 ```java
 class Solution {
-    public boolean validPalindrome(String s) {
-        for (int i = 0, j = s.length() - 1; i < j; ++i, --j) {
-            if (s.charAt(i) != s.charAt(j)) {
-                return check(s, i + 1, j) || check(s, i, j - 1);
+    private char[] s;
+
+    public boolean validPalindrome(String S) {
+        this.s = S.toCharArray();
+        for (int i = 0, j = s.length - 1; i < j; ++i, --j) {
+            if (s[i] != s[j]) {
+                return check(i + 1, j) || check(i, j - 1);
             }
         }
         return true;
     }
 
-    private boolean check(String s, int i, int j) {
+    private boolean check(int i, int j) {
         for (; i < j; ++i, --j) {
-            if (s.charAt(i) != s.charAt(j)) {
+            if (s[i] != s[j]) {
                 return false;
             }
         }
@@ -117,18 +120,17 @@ class Solution {
 class Solution {
 public:
     bool validPalindrome(string s) {
-        for (int i = 0, j = s.size() - 1; i < j; ++i, --j) {
-            if (s[i] != s[j]) {
-                return check(s, i + 1, j) || check(s, i, j - 1);
+        auto check = [&](int i, int j) {
+            for (; i < j; ++i, --j) {
+                if (s[i] != s[j]) {
+                    return false;
+                }
             }
-        }
-        return 1;
-    }
-
-    bool check(string s, int i, int j) {
-        for (; i < j; ++i, --j) {
+            return true;
+        };
+        for (int i = 0, j = s.size() - 1; i < j; ++i, --j) {
             if (s[i] != s[j]) {
-                return false;
+                return check(i + 1, j) || check(i, j - 1);
             }
         }
         return true;
@@ -161,18 +163,17 @@ func validPalindrome(s string) bool {
 
 ```ts
 function validPalindrome(s: string): boolean {
-    for (let i: number = 0, j = s.length - 1; i < j; ++i, --j) {
-        if (s.charAt(i) != s.charAt(j)) {
-            return isPalinddrome(s.slice(i, j)) || isPalinddrome(s.slice(i + 1, j + 1));
+    const check = (i: number, j: number): boolean => {
+        for (; i < j; ++i, --j) {
+            if (s[i] !== s[j]) {
+                return false;
+            }
         }
-    }
-    return true;
-}
-
-function isPalinddrome(s: string): boolean {
-    for (let i: number = 0, j = s.length - 1; i < j; ++i, --j) {
-        if (s.charAt(i) != s.charAt(j)) {
-            return false;
+        return true;
+    };
+    for (let i = 0, j = s.length - 1; i < j; ++i, --j) {
+        if (s[i] !== s[j]) {
+            return check(i + 1, j) || check(i, j - 1);
         }
     }
     return true;
@@ -187,16 +188,16 @@ function isPalinddrome(s: string): boolean {
  * @return {boolean}
  */
 var validPalindrome = function (s) {
-    let check = function (i, j) {
+    const check = function (i, j) {
         for (; i < j; ++i, --j) {
-            if (s.charAt(i) != s.charAt(j)) {
+            if (s[i] !== s[j]) {
                 return false;
             }
         }
         return true;
     };
     for (let i = 0, j = s.length - 1; i < j; ++i, --j) {
-        if (s.charAt(i) != s.charAt(j)) {
+        if (s[i] !== s[j]) {
             return check(i + 1, j) || check(i, j - 1);
         }
     }
diff --git a/solution/0600-0699/0680.Valid Palindrome II/Solution.cpp b/solution/0600-0699/0680.Valid Palindrome II/Solution.cpp
index 81411d025636e..fed27c2bb3771 100644
--- a/solution/0600-0699/0680.Valid Palindrome II/Solution.cpp	
+++ b/solution/0600-0699/0680.Valid Palindrome II/Solution.cpp	
@@ -1,20 +1,19 @@
 class Solution {
 public:
     bool validPalindrome(string s) {
-        for (int i = 0, j = s.size() - 1; i < j; ++i, --j) {
-            if (s[i] != s[j]) {
-                return check(s, i + 1, j) || check(s, i, j - 1);
+        auto check = [&](int i, int j) {
+            for (; i < j; ++i, --j) {
+                if (s[i] != s[j]) {
+                    return false;
+                }
             }
-        }
-        return 1;
-    }
-
-    bool check(string s, int i, int j) {
-        for (; i < j; ++i, --j) {
+            return true;
+        };
+        for (int i = 0, j = s.size() - 1; i < j; ++i, --j) {
             if (s[i] != s[j]) {
-                return false;
+                return check(i + 1, j) || check(i, j - 1);
             }
         }
         return true;
     }
-};
\ No newline at end of file
+};
diff --git a/solution/0600-0699/0680.Valid Palindrome II/Solution.java b/solution/0600-0699/0680.Valid Palindrome II/Solution.java
index b5935b48e052f..c9c7ae87808d3 100644
--- a/solution/0600-0699/0680.Valid Palindrome II/Solution.java	
+++ b/solution/0600-0699/0680.Valid Palindrome II/Solution.java	
@@ -1,19 +1,22 @@
 class Solution {
-    public boolean validPalindrome(String s) {
-        for (int i = 0, j = s.length() - 1; i < j; ++i, --j) {
-            if (s.charAt(i) != s.charAt(j)) {
-                return check(s, i + 1, j) || check(s, i, j - 1);
+    private char[] s;
+
+    public boolean validPalindrome(String S) {
+        this.s = S.toCharArray();
+        for (int i = 0, j = s.length - 1; i < j; ++i, --j) {
+            if (s[i] != s[j]) {
+                return check(i + 1, j) || check(i, j - 1);
             }
         }
         return true;
     }
 
-    private boolean check(String s, int i, int j) {
+    private boolean check(int i, int j) {
         for (; i < j; ++i, --j) {
-            if (s.charAt(i) != s.charAt(j)) {
+            if (s[i] != s[j]) {
                 return false;
             }
         }
         return true;
     }
-}
\ No newline at end of file
+}
diff --git a/solution/0600-0699/0680.Valid Palindrome II/Solution.js b/solution/0600-0699/0680.Valid Palindrome II/Solution.js
index 0b49415f3e812..6367de062eb9b 100644
--- a/solution/0600-0699/0680.Valid Palindrome II/Solution.js	
+++ b/solution/0600-0699/0680.Valid Palindrome II/Solution.js	
@@ -3,16 +3,16 @@
  * @return {boolean}
  */
 var validPalindrome = function (s) {
-    let check = function (i, j) {
+    const check = function (i, j) {
         for (; i < j; ++i, --j) {
-            if (s.charAt(i) != s.charAt(j)) {
+            if (s[i] !== s[j]) {
                 return false;
             }
         }
         return true;
     };
     for (let i = 0, j = s.length - 1; i < j; ++i, --j) {
-        if (s.charAt(i) != s.charAt(j)) {
+        if (s[i] !== s[j]) {
             return check(i + 1, j) || check(i, j - 1);
         }
     }
diff --git a/solution/0600-0699/0680.Valid Palindrome II/Solution.ts b/solution/0600-0699/0680.Valid Palindrome II/Solution.ts
index 0a19acc25e2f5..1481e67171aa1 100644
--- a/solution/0600-0699/0680.Valid Palindrome II/Solution.ts	
+++ b/solution/0600-0699/0680.Valid Palindrome II/Solution.ts	
@@ -1,16 +1,15 @@
 function validPalindrome(s: string): boolean {
-    for (let i: number = 0, j = s.length - 1; i < j; ++i, --j) {
-        if (s.charAt(i) != s.charAt(j)) {
-            return isPalinddrome(s.slice(i, j)) || isPalinddrome(s.slice(i + 1, j + 1));
+    const check = (i: number, j: number): boolean => {
+        for (; i < j; ++i, --j) {
+            if (s[i] !== s[j]) {
+                return false;
+            }
         }
-    }
-    return true;
-}
-
-function isPalinddrome(s: string): boolean {
-    for (let i: number = 0, j = s.length - 1; i < j; ++i, --j) {
-        if (s.charAt(i) != s.charAt(j)) {
-            return false;
+        return true;
+    };
+    for (let i = 0, j = s.length - 1; i < j; ++i, --j) {
+        if (s[i] !== s[j]) {
+            return check(i + 1, j) || check(i, j - 1);
         }
     }
     return true;