problem_Set_LeetCode

## **🔁 Loops (10)**  
- 🔄 [7] Reverse Integer  
- 🔄 [9] [Palindrome Number](https://leetcode.com/problems/palindrome-number)  
- 🔢 [258] Add Digits  
- 😊 [202] Happy Number  
- 🔢 [2520] Count the Digits That Divide a Number  
- 🔢 [728] Self Dividing Numbers  
- ✅ [507] Perfect Number  
- ⚽ [1742] Maximum Number of Balls in a Box  
- 🤢 [263] Ugly Number  
- 🏁 [1342] Number of Steps to Reduce a Number to Zero  

---

## **🟢 Easy Problems**  
- 🔠 [13] Roman to Integer  
- 🔄 [9] Palindrome Number  
- ✖️ [326] Power of Three  
- 📊 [171] Excel Sheet Column Number  
- 🎉 [412] Fizz Buzz  
- ➗ [231] Power of Two  
- 🎭 [190] Reverse Bits  
- 🔢 [191] Number of 1 Bits  

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## **🟡 Medium Problems**  
- 🧮 [50] Pow(x, n)  
- 🧩 [166] Fraction to Recurring Decimal  
- ➗ [227] Basic Calculator II  
- 🔢 [12] Integer to Roman  
- ✖️ [43] Multiply Strings  
- 🔠 [151] Reverse Words in a String  
- 📏 [8] String to Integer (atoi)  
- 🔢 [29] Divide Two Integers  

---

## **📌 Maps and Vectors (6)**  
- 🔠 [242] [Valid Anagram](https://leetcode.com/problems/valid-anagram)  
- 🔠 [2273] [Find Resultant Array After Removing Anagrams](https://leetcode.com/problems/find-resultant-array-after-removing-anagrams)  
- 🏷️ [49] [Group Anagrams](https://leetcode.com/problems/group-anagrams)  
- 📉 [448] Find All Numbers Disappeared in an Array  
- 🔍 [442] Find All Duplicates in an Array  
- 🎭 [645] Set Mismatch  

---

## **📦 Arrays (19)**  
- 🔢 [204] Count Primes  
- ❌ [27] [Remove Element](https://leetcode.com/problems/remove-element)  
- ❌ [26] [Remove Duplicates from Sorted Array](https://leetcode.com/problems/remove-duplicates-from-sorted-array)  
- ⚙️ [2460] [Apply Operations to an Array](https://leetcode.com/problems/apply-operations-to-an-array)  
- 🚀 [283] [Move Zeroes](https://leetcode.com/problems/move-zeroes)  
- 📌 [80] [Remove Duplicates from Sorted Array II](https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii)  
- ➕ [66] [Plus One](https://leetcode.com/problems/plus-one)  
- 🎨 [75] [Sort Colors](https://leetcode.com/problems/sort-colors)  
- 🔠 [58] [Length of Last Word](https://leetcode.com/problems/length-of-last-word)  
- 🔄 [88] Merge Sorted Array  
- ➗ [169] Majority Element  
- 📌 [217] Contains Duplicate  

---

## **🔄 Recursion (6)**  
- 🔢 [50] Pow(x, n)  
- 🌀 [509] [Fibonacci Number](https://leetcode.com/problems/fibonacci-number)  
- 🔗 [797] All Paths From Source to Target (Graph)  
- 🎯 [494] Target Sum  
- 🤹‍♂️ [241] Different Ways to Add Parentheses  
- 🔄 [60] Permutation Sequence  

---

## **🔑 HashSet (3)**  
- 🔢 [705] [Design HashSet](https://leetcode.com/problems/design-hashset)  
- 🔢 [706] [Design HashMap](https://leetcode.com/problems/design-hashmap)  
- 💎 [771] Jewels and Stones  

---

## **📈 Dynamic Programming (9)**  
- 🏃‍♂️ [70] [Climbing Stairs](https://leetcode.com/problems/climbing-stairs)  
- 🏠 [198] [House Robber](https://leetcode.com/problems/house-robber)  
- 🔄 [509] [Fibonacci Number](https://leetcode.com/problems/fibonacci-number)  
- 🏁 [746] [Min Cost Climbing Stairs](https://leetcode.com/problems/min-cost-climbing-stairs)  
- 🏡 [213] [House Robber II](https://leetcode.com/problems/house-robber-ii)  
- 🎭 [322] Coin Change  
-     Problem 121 Best Time to Buy and Sell Stock - LeetCode
-	    118. Pascal's Triangle
-	    62. Unique Paths


---

## **📊 Prefix Sum (3)**  
- 🔢 [1480] [Running Sum of 1D Array](https://leetcode.com/problems/running-sum-of-1d-array)  
- ➕ [53] Maximum Subarray  
- 📈 [1413] [Minimum Value to Get Positive Step-by-Step Sum](https://leetcode.com/problems/minimum-value-to-get-positive-step-by-step-sum)  

---

## **📦 Stacks and Queues (10)**  
- 📚 [225] Implement Stack using Queues  
- 🛒 [232] Implement Queue using Stacks  
- 🍽️ [1700] Number of Students Unable to Eat Lunch  
- 🔠 [20] Valid Parentheses  
- 💧 [42] [Trapping Rain Water](https://leetcode.com/problems/trapping-rain-water)  
- 🔢 [496] Next Greater Element I  
- 🔢 [503] Next Greater Element II  
- ⏳ [2073] Time Needed to Buy Tickets  
- 🧩 [155] Min Stack  
- 🔄 [739] Daily Temperatures  

---

## **📏 Sliding Window (8)**  
- 🔄 [3] [Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters)  
- 🎯 [209] [Minimum Size Subarray Sum](https://leetcode.com/problems/minimum-size-subarray-sum)  
- 🔍 [1876] Substrings of Size Three with Distinct Characters  
- 🔄 [567] Permutation in String  
- ⚠️ [219] [Contains Duplicate II](https://leetcode.com/problems/contains-duplicate-ii)  
- 📊 [643] [Maximum Average Subarray I](https://leetcode.com/problems/maximum-average-subarray-i)  
- 🏷️ [424] Longest Repeating Character Replacement  


## **🔎 Binary Search (7)**
🎯 [704] Binary Search
📈 [278] First Bad Version
➗ [35] Search Insert Position
🔍 [374] Guess Number Higher or Lower
🏹 [852] Peak Index in a Mountain Array
🔢 [162] Find Peak Element
📊 [153] Find Minimum in Rotated Sorted Array

---

##🔗 **Linked List (10)**
🔗 [206] Reverse Linked List
🔄 [21] Merge Two Sorted Lists
🚀 [141] Linked List Cycle
🔄 [83] Remove Duplicates from Sorted List
🔢 [2] Add Two Numbers
🔍 [160] Intersection of Two Linked Lists
🔥 [234] Palindrome Linked List
⏩ [19] Remove Nth Node From End of List
🛑 [203] Remove Linked List Elements
🔄 [24] Swap Nodes in Pairs


##🔗 **Doubly Linked List (4)**
🔄 [707] Design Linked List
🔄 [430] Flatten a Multilevel Doubly Linked List
🔄 [146] LRU Cache (Doubly Linked List)
🔄 [25] Reverse Nodes in k-Group

---
## 🌲 **Trees (8)**
🌳 [104] Maximum Depth of Binary Tree
🌱 [100] Same Tree
🔄 [101] Symmetric Tree
🏡 [102] Binary Tree Level Order Traversal
🔍 [144] Binary Tree Preorder Traversal
🔍 [94] Binary Tree Inorder Traversal
🔄 [145] Binary Tree Postorder Traversal
🔗 [226] Invert Binary Tree