Merge branch 'CodeHarborHub:main' into leetcode30

Author: VaishnaviMankala19

blog/getting-started-with-mern/output1.png

@@ -314,4 +314,4 @@ Here's a step-by-step algorithm for generating all possible letter combinations
    - Call the backtracking function with the initial index set to 0 and an empty string as the initial combination.
    - Return the list of combinations.
 
-This algorithm ensures that all possible combinations are generated by exploring all valid paths through backtracking.
+This algorithm ensures that all possible combinations are generated by exploring all valid paths through backtracking.

blog/getting-started-with-mern/output2.png

@@ -0,0 +1,121 @@
+---
+id: single-number
+title: Single Number
+sidebar_label: 0136 Single Number
+tags:
+  - Java
+  - Python
+  - C++
+  - XOR
+description: "This is a solution to the Single Number problem on LeetCode."
+---
+
+## Problem Description
+
+Given a non-empty array of integers nums, every element appears twice except for one. Find that single one.
+
+You must implement a solution with a linear runtime complexity and use only constant extra space.
+
+### Examples
+
+**Example 1:**
+
+```
+Input: nums = [2,2,1]
+Output: 1
+
+```
+
+**Example 2:**
+
+Input: nums = [4,1,2,1,2]
+Output: 4
+
+**Example 3:**
+
+```
+Input: nums = [1]
+Output: 1
+```
+
+### Constraints
+
+- $1 \leq nums.length \leq 3 * 10^4$
+- $-3 \times 10^4 \leq nums[i] \leq 3 \times 10^4$
+- Each element in the array appears twice except for one element which appears only once.
+
+---
+
+## Solution for Single Number Problem
+
+### Intuition
+
+When faced with this problem, the first hurdle to overcome is the strict limitations imposed on the solution: linear time complexity and constant space complexity. This means traditional methods of identifying duplicates like hash tables or sorting won't cut it. Instead, we'll need to use a different kind of magic, one rooted in the world of bitwise operations!
+
+### Approach
+
+Our saviour here is the XOR operation. XOR stands for 'exclusive or', and the magic lies in its properties. When a number is XORed with itself, the result is 0. And when a number is XORed with 0, the result is the number itself.
+
+So, if we XOR all the numbers in the array, all the numbers appearing twice will cancel each other out and we'll be left with the single number that appears only once.
+
+#### Code in Different Languages
+
+<Tabs>
+  <TabItem value="Java" label="Java">
+  <SolutionAuthor name="@vanAmsen"/>
+   ```java
+   class Solution {
+    public int singleNumber(int[] nums) {
+        int result = 0; 
+        for (int num : nums) { 
+            result ^= num; 
+        } 
+        return result;                                                
+    }
+}
+
+`````
+</TabItem>
+<TabItem value="Python" label="Python">
+<SolutionAuthor name="@vanAmsen"/>
+
+````python
+class Solution:
+    def singleNumber(self, nums: List[int]) -> int:
+        result = 0
+        for num in nums:
+            result ^= num
+        return result
+
+`````
+
+</TabItem>
+<TabItem value="C++" label="C++">
+<SolutionAuthor name="@vanAmsen"/>
+```cpp
+class Solution {
+public:
+    int singleNumber(vector<int>& nums) {
+        int result = 0; 
+        for (int num : nums) { 
+            result ^= num; 
+        } 
+        return result;                                            
+    }
+};
+
+```
+</TabItem>
+</Tabs>
+
+#### Complexity Analysis
+
+- Time complexity: $O(n)$, as we're iterating over the array only once.
+- Space complexity: $O(1)$, because we're only using a single variable to store the result,        irrespective of the size of the input.
+
+## References
+
+- **LeetCode Problem:** [Single Number](https://leetcode.com/problems/single-number/description/)
+- **Solution Link:** [Single NUmber on LeetCode](https://leetcode.com/problems/single-number/solutions/3801367/video-single-number-a-bitwise-magic-trick/)
+- **Authors Leetcode Profile:** [vanAmsen](https://leetcode.com/u/vanAmsen/)
+```

blog/getting-started-with-mern/output3.png

@@ -44,14 +44,23 @@
 }
 
 .resources-section .resources-container .resources-filters {
-  display: inline-flex;
-  gap: 0.25rem;
-  margin-bottom: 1.5rem;
+  display: grid;
+  grid-auto-flow: column;
+  grid-auto-columns: max-content;
+  gap: 10px;
+  margin: 1.5rem 0;
   border-radius: 0.5rem;
   padding: 0.5rem;
   font-family: "Jakarta", sans-serif;
   font-size: 0.875rem;
-  font-weight: 600;
+  font-weight: 600;  
+  scroll-behavior: smooth;
+  overflow-x: auto;
+  white-space: nowrap;
+  -ms-overflow-style: none;
+  scrollbar-width: none;
+  background-color: #07574e73;
+  border: 1px solid #666;
 }
 
 .bg-secondary-700 {
@@ -98,6 +107,8 @@
   .resource {
   text-decoration: none;
   color: inherit;
+  border-radius: 0.5rem;
+  box-shadow: 0 0 10px rgba(5, 174, 216, 0.386);
 }
 
 .resources-section
@@ -155,6 +166,7 @@
   .resource-title {
   font-weight: 600;
   margin-bottom: 8px;
+  padding: 0 0.5rem;
 }
 
 .resources-section
@@ -163,6 +175,7 @@
   .resources-grid
   .resource-description {
     line-height: 1.375;
+    padding: 0 0.5rem;
 }
 
 .resources-section
@@ -180,13 +193,15 @@
   .resources-grid
   .resource-duration {
   font-size: 14px;
-  color: #666;
+  padding: 0.5rem;
+  color: var(--ifm-color-primary);
 }
 
 .resources-section .resources-container .pagination {
   display: flex;
   justify-content: center;
   gap: 1rem;
+  margin-top: 2.5rem;
 }
 
 .resources-section .resources-container .pagination .pagination-button {

dsa-solutions/lc-solutions/0000-0099/0017-letter-combinations-of-a-phone-number.md

@@ -128,4 +128,15 @@ export const Users: User[] = [
     source: "https://github.com/ParnaRoyChowdhury777/ScanMe",
     tags: ["opensource", "product", "html", "css", "javascript", "vanilla"],
   },
+  {
+    title: "Captcha-Code Generator",
+    description:
+      "It generates a Captcha code based on the user's input and validates the user's input with the generated Captcha code.",
+    preview: require("./showcase/captcha-code.png"),
+    website:
+      "https://50-days-50-web-project.vercel.app/captcha/captcha.html",
+    source:
+      "https://github.com/dhairyagothi/50_days_50_web_project/tree/Main/public/captcha",
+    tags: ["html", "css", "javascript"],
+  },
 ];