Freaks City

203. Remove Linked List Elements Given the head of a linked list and an integer val, remove all nodes with value equal to val and return the new head. public ListNode removeElements(ListNode head, int val) { while (head != null && head.val == val) { head = head.next; } if (head == null) return null; ListNode pre ...

Given N assignments each with a maximum score a_i, two studeents (Ke and Do) score b_i% and c_i% of the maximum respetcively. Compute total weighted scores and detemrine who has the higher total.

Finding the Kth Node from the End of a Linked List To locate the kth node from the end efficient, use two pointers—fast and slow. Advance the fast pointer by k steps first. Then move both pointers forward until fast reaches the end. At this point, slow will be pointing to the desired node. int kthToLast(struct ListNode* head, int k) { struc ...

Questions Multiple Choice Questions The basic unit of data is ( ). A. Data Structure B. Data Element C. Data Item D. File In logical terms, data structures can be classified into ( ). A. Dynamic and Static Structures B. Compact and Non-compact Structures C. Internal and External Structures D. Linear and Non-linear Structures The condition for a ...

Abstract Data TypesAbstract Data Types (ADTs) form the foundation of data structure design. An ADT consists of three main components: data objects, basic operations, and data relationships. The implementation details are hidden from the user, allowing for modular and maintainable code design.Linear Data StructuresSequential ListsSequential list ...

Swapping Nodes in Pairs Problem: Given a linked list, swap every two adjacent nodes and return its head. Iterative Approach: class ListNode { int val; ListNode next; ListNode(int val) { this.val = val; } } class Solution { public ListNode swapPairs(ListNode head) { if (head == null || head.next == null) { ...

Given an array where every element appears twice except two elements that appear only once, find those two unique numbers. Approach 1: Frequency Counting with Index Mapping This method uses a temporary array to count occurrences by treating the original values as indices in the counting array. #include <stdio.h> int main() { int arr[ ...

Swapping Nodes in PairsApproach: Using a dummy head nodeLogic: Create a dummy head node to simplify the swapping process. Use a current pointer that moves forward two steps at a time. The loop continues as long as there are at least two more nodes to swap.Implementation:/** * Definition for singly-linked list. * struct ListNode { * int v ...

Evaluating Reverse Polish Notation Reverse Polish Notation (RPN) eliminates the need for parentheses by placing operators after their operands. A stack-based approach efficiently processes tokens in a single pass. class Solution { public: int evalRPN(vector<string>& expr) { stack<int> eval_stack; for (const a ...

Given $n$ closed intervals on a number line, the objective is to select exactly $m$ intervals such that they share at least one common coordinate point. The cost of a selection is defined as the difference between the maximum length and the minimum length among the chosen intervals. The length of an interval $[l, r]$ is calculated as $r - l$. T ...