LeetCode 2095 – Delete the Middle Node of a Linked List Solved: Delete the middle node in a linked list Used slow & fast pointers to find middle Then skipped the middle by adjusting links O(n) time, O(1) space #LeetCode #100DaysOfCode #LinkedList #DSA #PythonDSA

LeetCode 19 – Remove Nth Node From End of List Solved: Remove the nth node from end Two-pointer approach → move fast n steps ahead, then move both till fast hits end Adjust links to skip target node O(n) time, O(1) space #LeetCode #100DaysOfCode #LinkedList #DSA #PythonDSA

LeetCode 328 – Odd Even Linked List Solved: Group all odd-indexed nodes, then even-indexed nodes Maintained two lists (odd & even) → connected at the end O(n) time, O(1) space Good practice in rearranging linked lists! #LeetCode #100DaysOfCode #LinkedList #DSA #PythonDSA

LeetCode 234 – Palindrome Linked List Solved: Check if a linked list is a palindrome Steps: Find middle (slow & fast pointers) Reverse 2nd half of list Compare first & second half nodes O(n) time, O(1) space #LeetCode #100DaysOfCode #LinkedList #DSA #PythonDSA

LeetCode 876 – Middle of the Linked List Solved: Find middle node of a linked list Used slow & fast pointers → when fast hits end, slow is at middle O(n) time, O(1) space Clean & elegant pointer trick! #LeetCode #100DaysOfCode #LinkedList #DSA #PythonDSA

LeetCode 142 – Linked List Cycle II Solved: Detect cycle and return starting node Step 1: Use Floyd’s Cycle Detection (slow & fast) Step 2: Once they meet, move one pointer to head→ step both by 1→meet at cycle start O(n) time, O(1) space #LeetCode #LinkedList #DSA #PythonDSA

LeetCode 2396 – Strictly Palindromic Number Solved: Check if n is palindromic in every base 2…n-2 Trick: No number ≥ 4 can ever be strictly palindromic → always false Math observation > brute force! #LeetCode #100DaysOfCode #Math #PythonDSA

LeetCode 141 – Linked List Cycle Solved: Detect cycle in a linked list Used Floyd’s Cycle Detection (slow & fast pointers) If pointers meet → cycle exists O(n) time, O(1) space #LeetCode #100DaysOfCode #LinkedList #DSA #PythonDSA

LeetCode 206 – Reverse Linked List Solved: Reverse a singly linked list Iterative: keep track of prev, curr, next Re-point curr.next → prev until null Classic linked list must-know! #LeetCode #100DaysOfCode #LinkedList #DSA #PythonDSA

LeetCode 237 – Delete Node in a Linked List Solved: Delete a node (not head) in a singly linked list Trick: Copy value from next into current node → skip next O(1) time, O(1) space Simple yet clever linked list manipulation! #LeetCode #100DaysOfCode #LinkedList #PythonDSA

Haven’t posted here for a few days… but I’ve been solving daily on LeetCode Getting back to posting solutions again from today #100DaysOfCode #LeetCode #DSA #PythonDSA

LeetCode Contest Update Q1. Restore Finishing Order Submitted in today’s contest! Idea: Use given ranks to rebuild correct order by mapping participants back to their positions. Efficient simulation with array/indexing. #LeetCode #Contest #100DaysOfCode #DSA #PythonDSA

LeetCode 1283 – Find the Smallest Divisor Given a Threshold Find the smallest divisor so that sum of [num/div]≤threshold Used binary search on divisor range[1…max(nums)] For each mid, compute sum If sum-threshold:increase divisor Else:shrink search space #LeetCode #PythonDSA

LeetCode 1614 – Maximum Nesting Depth of Parentheses Solved: Find max depth of nested parentheses Traverse string, increment on '(',decrement on ')' Track maximum depth reached O(n) time, O(1)space Simple yet useful stack-like logic! #LeetCode #100DaysOfCode #PythonDSA #Strings

LeetCode 8 – String to Integer (atoi) Solved: Convert string to 32-bit signed integer Steps: Ignore leading spaces Handle sign + / - Build number till non-digit Clamp to integer range Classic string parsing problem! #LeetCode #100DaysOfCode #PythonDSA #Strings #DSA

LeetCode 451 – Sort Characters By Frequency Solved: Sort string chars by decreasing frequency Count freq with hashmap → sort by count → rebuild string O(n log n) time, O(n) space Great practice for hashmaps + sorting! #LeetCode #100DaysOfCode #HashMap #PythonDSA #Strings

LeetCode 796 – Rotate String Solved: Check if one string is rotation of another Trick: s2 must be a substring of s1 + s1 Simple check with in operator O(n²) worst-case, O(1) extra space Neat and elegant string trick! #LeetCode #100DaysOfCode #PythonDSA #Strings #DSA

LeetCode 205 – Isomorphic Strings Solved: Check if two strings follow the same pattern Used two hash maps to track character mappings both ways Ensures one-to-one mapping between characters O(n) time, O(1) space (fixed alphabet) #LeetCode #100DaysOfCode #HashMap #PythonDSA #DSA

LeetCode 540 – Single Element in a Sorted Array Find element that appears once in sorted array Binary search with index parity logic Pairs start at even index before single element Shift search space based on mid’s pairing O(log n) time, O(1) space #BinarySearch #DSA #PythonDSA

LeetCode 153 – Find Minimum in Rotated Sorted Array Solved: Find smallest element in rotated sorted array Used binary search Compared mid with right to decide search side O(log n) time, O(1) space Elegant and efficient! #LeetCode #100DaysOfCode #BinarySearch #DSA #PythonDSA