diff --git a/leetcode/392. Is Subsequence/README.md b/leetcode/392. Is Subsequence/README.md
index 563c12fa..26c70b4e 100644
--- a/leetcode/392. Is Subsequence/README.md	
+++ b/leetcode/392. Is Subsequence/README.md	
@@ -1,14 +1,8 @@
 # [392. Is Subsequence (Easy)](https://leetcode.com/problems/is-subsequence/)
 
-<p>Given a string <b>s</b> and a string <b>t</b>, check if <b>s</b> is subsequence of <b>t</b>.</p>
+<p>Given two strings <code>s</code> and <code>t</code>, return <code>true</code><em> if </em><code>s</code><em> is a <strong>subsequence</strong> of </em><code>t</code><em>, or </em><code>false</code><em> otherwise</em>.</p>
 
-<p>A subsequence of a string is a new string which is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remaining characters. (ie, <code>"ace"</code> is a subsequence of <code>"abcde"</code> while <code>"aec"</code> is not).</p>
-
-<p><b>Follow up:</b><br>
-If there are lots of incoming S, say S1, S2, ... , Sk where k &gt;= 1B, and you want to check one by one to see if T has its subsequence. In this scenario, how would you change your code?</p>
-
-<p><b>Credits:</b><br>
-Special thanks to <a href="https://leetcode.com/pbrother/">@pbrother</a> for adding this problem and creating all test cases.</p>
+<p>A <strong>subsequence</strong> of a string is a new string that is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remaining characters. (i.e., <code>"ace"</code> is a subsequence of <code>"<u>a</u>b<u>c</u>d<u>e</u>"</code> while <code>"aec"</code> is not).</p>
 
 <p>&nbsp;</p>
 <p><strong>Example 1:</strong></p>
@@ -23,19 +17,24 @@ Special thanks to <a href="https://leetcode.com/pbrother/">@pbrother</a> for add
 
 <ul>
 	<li><code>0 &lt;= s.length &lt;= 100</code></li>
-	<li><code>0 &lt;= t.length &lt;= 10^4</code></li>
-	<li>Both strings consists only of lowercase characters.</li>
+	<li><code>0 &lt;= t.length &lt;= 10<sup>4</sup></code></li>
+	<li><code>s</code> and <code>t</code> consist only of lowercase English letters.</li>
 </ul>
 
+<p>&nbsp;</p>
+<strong>Follow up:</strong> Suppose there are lots of incoming <code>s</code>, say <code>s<sub>1</sub>, s<sub>2</sub>, ..., s<sub>k</sub></code> where <code>k &gt;= 10<sup>9</sup></code>, and you want to check one by one to see if <code>t</code> has its subsequence. In this scenario, how would you change your code?
+
+**Companies**:  
+[Adobe](https://leetcode.com/company/adobe), [Amazon](https://leetcode.com/company/amazon), [Google](https://leetcode.com/company/google)
 
 **Related Topics**:  
-[Binary Search](https://leetcode.com/tag/binary-search/), [Dynamic Programming](https://leetcode.com/tag/dynamic-programming/), [Greedy](https://leetcode.com/tag/greedy/)
+[Two Pointers](https://leetcode.com/tag/two-pointers/), [String](https://leetcode.com/tag/string/), [Dynamic Programming](https://leetcode.com/tag/dynamic-programming/)
 
 **Similar Questions**:
 * [Number of Matching Subsequences (Medium)](https://leetcode.com/problems/number-of-matching-subsequences/)
 * [Shortest Way to Form String (Medium)](https://leetcode.com/problems/shortest-way-to-form-string/)
 
-## Solution 1.
+## Solution 1. Two Pointers
 
 ```cpp
 // OJ: https://leetcode.com/problems/is-subsequence/
diff --git a/leetcode/392. Is Subsequence/s1.cpp b/leetcode/392. Is Subsequence/s1.cpp
deleted file mode 100644
index 2a4d7949..00000000
--- a/leetcode/392. Is Subsequence/s1.cpp	
+++ /dev/null
@@ -1,14 +0,0 @@
-// OJ: https://leetcode.com/problems/is-subsequence/
-// Author: github.com/lzl124631x
-// Time: O(M + N)
-// Space: O(1)
-class Solution {
-public:
-    bool isSubsequence(string s, string t) {
-        int i = 0, j = 0, M = s.size(), N = t.size();
-        for (; i < M && j < N; ++j) {
-            if (s[i] == t[j]) ++i;
-        }
-        return i == M;
-    }
-};
\ No newline at end of file