Freaks City

Trimming a Binary Search Tree The task involves removing nodes from a binary search tree (BST) such that every remaining node's value falls within a specified range [low, high]. If the root node falls outside this range, the structure of the tree must be adjusted, potentially returning a new root. struct TreeNode* prune_bst(struct TreeNode* nod ...

Naive Linear Scan with Manual Shift This method iterates through the collection, identifying target values and shifting remaining items leftward to fill gaps. Each removal triggers a backward propagation of elements, resulting in quadratic time complexity. #include <stdio.h> int strip_target(int* arr, int capacity, int target) { int ...

Core ArrayList Methods Adding Elements The add(E e) method appends an element to the end of the list. ArrayList<String> names = new ArrayList<>(); boolean flag = names.add("Alice"); names.add("Bob"); names.add("Charlie"); names.add("David"); System.out.println(names); Removing Elements Two ...

Many applications feature referral systems where users earn commissions by inviting others. Consider a scenario where User A invites User B, and User B, in turn, invites User C. In this chain, User A is the ultimate referrer for both User B and User C. User A, however, has no ultimate referrer. This referral hierarchy is typically stored in a d ...

Function objects, frequently termed functors, allow C++ classes to emulate callable routines by overloading the operator(). This design pattern enables object instantiation that accepts parameters and yields return values identically to standard functions, while preserving encapsulated state and type safety. Unlike conventional function pointer ...

Binary Search in a Sorted Array Given a sorted array arr of n integers in ascending order and a target value target, implement a function to search for target within arr. Return the index if found; otherwise, return -1. The array contains no duplicate elements. Example 1: Input: arr = [-1, 0, 3, 5, 9, 12], target = 9 Output: 4 Example 2: Input ...

Collections Architecture and Fundamentals Java's collections framework establishes a standardized hierarchy for object aggregation and manipulation. The architecture comprises three fundamental layers: abstract interfaces defining container contracts, concrete implementations providing optimized storage mechanisms, and polymorphic algorithms fo ...

Dynamic Array Data Structure A linear list represents a finite sequence of elements sharing identical characteristics. Logically, it forms a continuous line, but its physical memory layout can vary. The dynamic array, a specific linear list implementation, reserves contiguous memory blocks to store elements, growing its allocated space when nec ...

Instantiation and Initial Setup Creating an empty dynamic array: std::vector<int> emptyVec; Initializing with a predefined set of values: std::vector<int> initialVec = {10, 20, 30, 40}; Setting a predefined size with a uniform default value: std::vector<int> sizedVec(5, -1); // Generates a vector with 5 elements, all set to -1 ...

Number Theory Utilities Greatest Common Divisor int gcd(int a, int b) { while (b) { int temp = b; b = a % b; a = temp; } return a; } Least Common Multiple int lcm(int a, int b) { return a / gcd(a, b) * b; } Fast Exponentiation long long power(long long base, long long exp) { long long result = 1; ...