Freaks City

House Robber class Solution: def rob(self, values: list[int]) -> int: n = len(values) if n == 0: return 0 if n == 1: return values[0] prev2 = values[0] prev1 = max(values[0], values[1]) for i in range(2, n): current = max(prev2 + values[ ...

A binary tree is a nonlinear data structure that models hierarchical relationships between parent and child nodes, embodying the divide-and-conquer principle. Like linked lists, its fundamental unit is a node containing a value, a pointer to the left child, and a pointer to the right child. // Node structure for a binary tree typedef struct Tre ...

Dynamic Programming: 0/1 Knapsack Problem This problem is a classic 0/1 knapsack implementation. The approach involves using dynamic programming where dp[j] represents the number of ways to order food items with exactly j yuan remaining. The recurrence relation is dp[j] = dp[j] + dp[j - a[i]], which means the original number of ways to have j y ...

Counting Valid Mountain SequencesTo solve the mountain sequence counting problem, we need to determine the number of permutations that satisfy the mountain property. This can be efficiently computed using combinatorial mathematics by recognizing patterns in the sorted sequence.#include <iostream> #include <vector> #include <algor ...

The problem presents a scenario involving a delivery network modeled as a tree structure. The network consists of N nodes (locations) connected by N-1 bidirectional roads, with no cycles. One specific node serves as the root (the delivery station). The goal is to determine the minimum distance required to visit all currently active delivery loc ...

Database Schema and Test Data Preparation To evaluate the processing efficiency of tree structures at scale, a relational model is established first. Table Structure Definition The schema utilizes a self-referencing foreign key to denote parent-child relationships. CREATE TABLE system_organization ( `id` bigint NOT NULL AUTO_INCREMENT, `par ...

N-ary Tree Preorder Traversal Given the root of an n-ary tree, return the preorder traversal of its nodes' values. /* class Node { public: int val; vector<Node*> children; Node() {} Node(int _val) { val = _val; } Node(int _val, vector<Node*> _children) { val = _val; children = _children; } }; ...

Binary trees are hierarchical data structures with nodes containing up to two children. Common types include full binary trees where every node has either zero or two children, and complete binary trees where all levels are fully filled except possibly the last level. Storage methods include linked storage using node references and sequential s ...

In a tree-structured neighborhood where the root represents the delivery station, a courier must visit all requested delivery nodes at least once. The goal is to compute, after each new delivery request, the shortest total distance required to deliver all orders so far—without needing to return to the root. The key insight is that traversing al ...

Lowest Common Ancestor in a BST (LeetCode 235) Given a BST and two nodes p and q, find their lowest common ancestor (LCA). The BST property allows an efficient traversal from root down: the LCA is the first node whose value lies between p->val and q->val (inclusive). Because the tree is ordered, moving left/right narrows down the range un ...