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diff --git a/solutions/01-matrix/description.md b/solutions/01-matrix/description.md
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+# [542. 01 Matrix](https://leetcode.com/problems/01-matrix/)
+
+<p style="color:orange;">Medium</p>
+
+<p>Given an <code>m x n</code> binary matrix <code>mat</code>, return <em>the distance of the nearest </em><code>0</code><em> for each cell</em>.</p>
+
+<p>The distance between two adjacent cells is <code>1</code>.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+<img alt="" src="https://assets.leetcode.com/uploads/2021/04/24/01-1-grid.jpg" style="width: 253px; height: 253px;" />
+<pre>
+<strong>Input:</strong> mat = [[0,0,0],[0,1,0],[0,0,0]]
+<strong>Output:</strong> [[0,0,0],[0,1,0],[0,0,0]]
+</pre>
+
+<p><strong class="example">Example 2:</strong></p>
+<img alt="" src="https://assets.leetcode.com/uploads/2021/04/24/01-2-grid.jpg" style="width: 253px; height: 253px;" />
+<pre>
+<strong>Input:</strong> mat = [[0,0,0],[0,1,0],[1,1,1]]
+<strong>Output:</strong> [[0,0,0],[0,1,0],[1,2,1]]
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>m == mat.length</code></li>
+	<li><code>n == mat[i].length</code></li>
+	<li><code>1 &lt;= m, n &lt;= 10<sup>4</sup></code></li>
+	<li><code>1 &lt;= m * n &lt;= 10<sup>4</sup></code></li>
+	<li><code>mat[i][j]</code> is either <code>0</code> or <code>1</code>.</li>
+	<li>There is at least one <code>0</code> in <code>mat</code>.</li>
+</ul>
+
diff --git a/solutions/132-pattern/description.md b/solutions/132-pattern/description.md
@@ -0,0 +1,42 @@
+# [456. 132 Pattern](https://leetcode.com/problems/132-pattern/)
+
+<p style="color:orange;">Medium</p>
+
+<p>Given an array of <code>n</code> integers <code>nums</code>, a <strong>132 pattern</strong> is a subsequence of three integers <code>nums[i]</code>, <code>nums[j]</code> and <code>nums[k]</code> such that <code>i &lt; j &lt; k</code> and <code>nums[i] &lt; nums[k] &lt; nums[j]</code>.</p>
+
+<p>Return <code>true</code><em> if there is a <strong>132 pattern</strong> in </em><code>nums</code><em>, otherwise, return </em><code>false</code><em>.</em></p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> nums = [1,2,3,4]
+<strong>Output:</strong> false
+<strong>Explanation:</strong> There is no 132 pattern in the sequence.
+</pre>
+
+<p><strong class="example">Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> nums = [3,1,4,2]
+<strong>Output:</strong> true
+<strong>Explanation:</strong> There is a 132 pattern in the sequence: [1, 4, 2].
+</pre>
+
+<p><strong class="example">Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> nums = [-1,3,2,0]
+<strong>Output:</strong> true
+<strong>Explanation:</strong> There are three 132 patterns in the sequence: [-1, 3, 2], [-1, 3, 0] and [-1, 2, 0].
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>n == nums.length</code></li>
+	<li><code>1 &lt;= n &lt;= 2 * 10<sup>5</sup></code></li>
+	<li><code>-10<sup>9</sup> &lt;= nums[i] &lt;= 10<sup>9</sup></code></li>
+</ul>
+
diff --git a/solutions/3sum-closest/description.md b/solutions/3sum-closest/description.md
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+# [16. 3Sum Closest](https://leetcode.com/problems/3sum-closest/)
+
+<p style="color:orange;">Medium</p>
+
+<p>Given an integer array <code>nums</code> of length <code>n</code> and an integer <code>target</code>, find three integers in <code>nums</code> such that the sum is closest to <code>target</code>.</p>
+
+<p>Return <em>the sum of the three integers</em>.</p>
+
+<p>You may assume that each input would have exactly one solution.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> nums = [-1,2,1,-4], target = 1
+<strong>Output:</strong> 2
+<strong>Explanation:</strong> The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).
+</pre>
+
+<p><strong class="example">Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> nums = [0,0,0], target = 1
+<strong>Output:</strong> 0
+<strong>Explanation:</strong> The sum that is closest to the target is 0. (0 + 0 + 0 = 0).
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>3 &lt;= nums.length &lt;= 500</code></li>
+	<li><code>-1000 &lt;= nums[i] &lt;= 1000</code></li>
+	<li><code>-10<sup>4</sup> &lt;= target &lt;= 10<sup>4</sup></code></li>
+</ul>
+
diff --git a/solutions/3sum/description.md b/solutions/3sum/description.md
@@ -0,0 +1,46 @@
+# [15. 3Sum](https://leetcode.com/problems/3sum/)
+
+<p style="color:orange;">Medium</p>
+
+<p>Given an integer array nums, return all the triplets <code>[nums[i], nums[j], nums[k]]</code> such that <code>i != j</code>, <code>i != k</code>, and <code>j != k</code>, and <code>nums[i] + nums[j] + nums[k] == 0</code>.</p>
+
+<p>Notice that the solution set must not contain duplicate triplets.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> nums = [-1,0,1,2,-1,-4]
+<strong>Output:</strong> [[-1,-1,2],[-1,0,1]]
+<strong>Explanation:</strong> 
+nums[0] + nums[1] + nums[2] = (-1) + 0 + 1 = 0.
+nums[1] + nums[2] + nums[4] = 0 + 1 + (-1) = 0.
+nums[0] + nums[3] + nums[4] = (-1) + 2 + (-1) = 0.
+The distinct triplets are [-1,0,1] and [-1,-1,2].
+Notice that the order of the output and the order of the triplets does not matter.
+</pre>
+
+<p><strong class="example">Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> nums = [0,1,1]
+<strong>Output:</strong> []
+<strong>Explanation:</strong> The only possible triplet does not sum up to 0.
+</pre>
+
+<p><strong class="example">Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> nums = [0,0,0]
+<strong>Output:</strong> [[0,0,0]]
+<strong>Explanation:</strong> The only possible triplet sums up to 0.
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>3 &lt;= nums.length &lt;= 3000</code></li>
+	<li><code>-10<sup>5</sup> &lt;= nums[i] &lt;= 10<sup>5</sup></code></li>
+</ul>
+
diff --git a/solutions/add-binary/description.md b/solutions/add-binary/description.md
@@ -0,0 +1,23 @@
+# [67. Add Binary](https://leetcode.com/problems/add-binary/)
+
+<p style="color:green;">Easy</p>
+
+<p>Given two binary strings <code>a</code> and <code>b</code>, return <em>their sum as a binary string</em>.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+<pre><strong>Input:</strong> a = "11", b = "1"
+<strong>Output:</strong> "100"
+</pre><p><strong class="example">Example 2:</strong></p>
+<pre><strong>Input:</strong> a = "1010", b = "1011"
+<strong>Output:</strong> "10101"
+</pre>
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= a.length, b.length &lt;= 10<sup>4</sup></code></li>
+	<li><code>a</code> and <code>b</code> consist&nbsp;only of <code>&#39;0&#39;</code> or <code>&#39;1&#39;</code> characters.</li>
+	<li>Each string does not contain leading zeros except for the zero itself.</li>
+</ul>
+
diff --git a/solutions/add-digits/description.md b/solutions/add-digits/description.md
@@ -0,0 +1,35 @@
+# [258. Add Digits](https://leetcode.com/problems/add-digits/)
+
+<p style="color:green;">Easy</p>
+
+<p>Given an integer <code>num</code>, repeatedly add all its digits until the result has only one digit, and return it.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> num = 38
+<strong>Output:</strong> 2
+<strong>Explanation:</strong> The process is
+38 --&gt; 3 + 8 --&gt; 11
+11 --&gt; 1 + 1 --&gt; 2 
+Since 2 has only one digit, return it.
+</pre>
+
+<p><strong class="example">Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> num = 0
+<strong>Output:</strong> 0
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>0 &lt;= num &lt;= 2<sup>31</sup> - 1</code></li>
+</ul>
+
+<p>&nbsp;</p>
+<p><strong>Follow up:</strong> Could you do it without any loop/recursion in <code>O(1)</code> runtime?</p>
+
diff --git a/solutions/add-strings/description.md b/solutions/add-strings/description.md
@@ -0,0 +1,39 @@
+# [415. Add Strings](https://leetcode.com/problems/add-strings/)
+
+<p style="color:green;">Easy</p>
+
+<p>Given two non-negative integers, <code>num1</code> and <code>num2</code> represented as string, return <em>the sum of</em> <code>num1</code> <em>and</em> <code>num2</code> <em>as a string</em>.</p>
+
+<p>You must solve the problem without using any built-in library for handling large integers (such as <code>BigInteger</code>). You must also not convert the inputs to integers directly.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> num1 = &quot;11&quot;, num2 = &quot;123&quot;
+<strong>Output:</strong> &quot;134&quot;
+</pre>
+
+<p><strong class="example">Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> num1 = &quot;456&quot;, num2 = &quot;77&quot;
+<strong>Output:</strong> &quot;533&quot;
+</pre>
+
+<p><strong class="example">Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> num1 = &quot;0&quot;, num2 = &quot;0&quot;
+<strong>Output:</strong> &quot;0&quot;
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= num1.length, num2.length &lt;= 10<sup>4</sup></code></li>
+	<li><code>num1</code> and <code>num2</code> consist of only digits.</li>
+	<li><code>num1</code> and <code>num2</code> don&#39;t have any leading zeros except for the zero itself.</li>
+</ul>
+
diff --git a/solutions/add-to-array-form-of-integer/description.md b/solutions/add-to-array-form-of-integer/description.md
@@ -0,0 +1,47 @@
+# [989. Add to Array-Form of Integer](https://leetcode.com/problems/add-to-array-form-of-integer/)
+
+<p style="color:green;">Easy</p>
+
+<p>The <strong>array-form</strong> of an integer <code>num</code> is an array representing its digits in left to right order.</p>
+
+<ul>
+	<li>For example, for <code>num = 1321</code>, the array form is <code>[1,3,2,1]</code>.</li>
+</ul>
+
+<p>Given <code>num</code>, the <strong>array-form</strong> of an integer, and an integer <code>k</code>, return <em>the <strong>array-form</strong> of the integer</em> <code>num + k</code>.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> num = [1,2,0,0], k = 34
+<strong>Output:</strong> [1,2,3,4]
+<strong>Explanation:</strong> 1200 + 34 = 1234
+</pre>
+
+<p><strong class="example">Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> num = [2,7,4], k = 181
+<strong>Output:</strong> [4,5,5]
+<strong>Explanation:</strong> 274 + 181 = 455
+</pre>
+
+<p><strong class="example">Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> num = [2,1,5], k = 806
+<strong>Output:</strong> [1,0,2,1]
+<strong>Explanation:</strong> 215 + 806 = 1021
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= num.length &lt;= 10<sup>4</sup></code></li>
+	<li><code>0 &lt;= num[i] &lt;= 9</code></li>
+	<li><code>num</code> does not contain any leading zeros except for the zero itself.</li>
+	<li><code>1 &lt;= k &lt;= 10<sup>4</sup></code></li>
+</ul>
+
diff --git a/solutions/add-two-numbers-ii/description.md b/solutions/add-two-numbers-ii/description.md
@@ -0,0 +1,42 @@
+# [445. Add Two Numbers II](https://leetcode.com/problems/add-two-numbers-ii/)
+
+<p style="color:orange;">Medium</p>
+
+<p>You are given two <strong>non-empty</strong> linked lists representing two non-negative integers. The most significant digit comes first and each of their nodes contains a single digit. Add the two numbers and return the sum as a linked list.</p>
+
+<p>You may assume the two numbers do not contain any leading zero, except the number 0 itself.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+<img alt="" src="https://assets.leetcode.com/uploads/2021/04/09/sumii-linked-list.jpg" style="width: 523px; height: 342px;" />
+<pre>
+<strong>Input:</strong> l1 = [7,2,4,3], l2 = [5,6,4]
+<strong>Output:</strong> [7,8,0,7]
+</pre>
+
+<p><strong class="example">Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> l1 = [2,4,3], l2 = [5,6,4]
+<strong>Output:</strong> [8,0,7]
+</pre>
+
+<p><strong class="example">Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> l1 = [0], l2 = [0]
+<strong>Output:</strong> [0]
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li>The number of nodes in each linked list is in the range <code>[1, 100]</code>.</li>
+	<li><code>0 &lt;= Node.val &lt;= 9</code></li>
+	<li>It is guaranteed that the list represents a number that does not have leading zeros.</li>
+</ul>
+
+<p>&nbsp;</p>
+<p><strong>Follow up:</strong>&nbsp;Could you solve it without reversing the input lists?</p>
+
diff --git a/solutions/add-two-numbers/description.md b/solutions/add-two-numbers/description.md
@@ -0,0 +1,40 @@
+# [2. Add Two Numbers](https://leetcode.com/problems/add-two-numbers/)
+
+<p style="color:orange;">Medium</p>
+
+<p>You are given two <strong>non-empty</strong> linked lists representing two non-negative integers. The digits are stored in <strong>reverse order</strong>, and each of their nodes contains a single digit. Add the two numbers and return the sum&nbsp;as a linked list.</p>
+
+<p>You may assume the two numbers do not contain any leading zero, except the number 0 itself.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+<img alt="" src="https://assets.leetcode.com/uploads/2020/10/02/addtwonumber1.jpg" style="width: 483px; height: 342px;" />
+<pre>
+<strong>Input:</strong> l1 = [2,4,3], l2 = [5,6,4]
+<strong>Output:</strong> [7,0,8]
+<strong>Explanation:</strong> 342 + 465 = 807.
+</pre>
+
+<p><strong class="example">Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> l1 = [0], l2 = [0]
+<strong>Output:</strong> [0]
+</pre>
+
+<p><strong class="example">Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> l1 = [9,9,9,9,9,9,9], l2 = [9,9,9,9]
+<strong>Output:</strong> [8,9,9,9,0,0,0,1]
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li>The number of nodes in each linked list is in the range <code>[1, 100]</code>.</li>
+	<li><code>0 &lt;= Node.val &lt;= 9</code></li>
+	<li>It is guaranteed that the list represents a number that does not have leading zeros.</li>
+</ul>
+