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Intersection of Linked Lists Problem Link LeetCode 160 Problem Statement Given the heads of two singly linked lists, headA and headB, return the node at which the two lists intesrect. If there is no intersection, return nullptr. The linked lists must retain their original structure after the function returns. You are not allowed to modify th ...

Problem Description You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order, and each node contains a single digit. Add the two numbers and return the sum as a linked list. You may assume the two numbers do not contain any leading zero, except the number 0 itself. Examples Example ...

Arrays and Strings Merging Sorted Arrays Naive Merge and Sort class Solution { public: void combineArrays(vector<int>& arr1, int m, vector<int>& arr2, int n) { for(int i = 0; i < n; ++i) { arr1[m + i] = arr2[i]; } sort(arr1.begin(), arr1.end()); } }; Two-Pointer Forward Merg ...

Unique Substrings in Wraparound String Given a string p, find the number of unique non-empty substrings of p that are also substrings of the infinite wraparound string "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz...". The infinite string repeats the alphabet sequence cyclically. DP Solution: We'll use a DP array where dp[i] r ...

Given a rectangular binary matrix representing a geographical map where character '1' indicates landmass and '0' represents water, the computational task is to enumerate distinct islands. An island forms when land cells connect horizontally or vertically; diagonal adjacency does not constitute valid connectivity. The grid periphery is assumed t ...

Reversing a Linnked List Problem: Given the head of a singly linked list, reverse the list and return the new head. Approach: Iterative Node Reversal To reverse a linked list iteratively, we can utilize three pointers: current, previous, and temporary. The current pointer traverses the list, while the previous pointer keeps track of the reverse ...

Given a string s, the objective is to locate and return longest substring that reads the same forwards and backwards. Examples Input: s = "babad" Output: "bab" Note: "aba" is also a valid answer. Input: s = "cbbd" Output: "bb" Input: s = "a" Output: "a" Input: s = "a ...

Given a m x n grid filled with non-negative numbers, find a path from the top-left corner to the bottom-right corner wich minimizes the sum of all numbers along its path. You can only move either down or right at any point in time. Approach: Dynamic Programming This problem is a classic example of dynamic porgramming. The key is to build a solu ...

1648. Sell Diminishing-Valued Colored Balls The objective is to maximize profit when selling balls whose values decrease by 1 after each sale. The optimal approach is a greedy strategy where we always sell the currently most valuable balls available. By sorting the inventory in descending order, we can visualize the stock as columns. We process ...

Binary search is a fundamental algorithm that efficiently locates target values in sorted arrays. This article explores several classic LeetCode problems that leverage binary search, along with related array manipulation techniques. Problem 704: Binary Search When performing binary search on a sorted array, the choice of boundary conditions sig ...