Freaks City

Problem 1: Find N Unique Integers Sum up to Zero Given an integer n, any array of n unique integers that sum to 0 can be returned. Example 1: Input: n = 5 Output: [-7,-1,1,3,4] Explanation: These arrays are also correct [-5,-1,1,2,3], [-3,-1,2,-2,4]. Example 2: Input: n = 3 Output: [-1,0,1] Example 3: Input: n = 1 Output: [0] Constraints: 1 &l ...

Bulb Switcher III There are n bulbs arranged in a line, numbered from 1 to n from left to right. Initially, all bulb are turned off. At time k (where k ranges from 0 to n-1), we turn on the bulb at position light[k]. A bulb turns blue when both conditions are met: The bulb is currently on All bulbs to its left are also on Return the number of ...

LeetCode Problem Link Problem Description: Given the root of a binary tree, check whether it is symmetric around its center. A binary tree is symmetric if the left subtree is a mirror reflection of the right subtree. Example 1: root = [1,2,2,3,4,4,3] Output: true Example 2: root = [1,2,2,null,3,null,3] Output: false Approach Analysis To determi ...

Finding the Bottom Left Tree ValueLocating the leftmost value in the last row of a binary tree can be efficiently achieved using Breadth-First Search (BFS). By processing the tree level by level, the first node encountered at each depth represents the leftmost node for that specific row. Upon completing the traversal, the value recorded for the ...

In-Order Traversal Recursive List<Integer> inorder(TreeNode node) { List<Integer> out = new ArrayList<>(); walk(node, out); return out; } void walk(TreeNode cur, List<Integer> acc) { if (cur == null) return; walk(cur.left, acc); acc.add(cur.val); walk(cur.right, acc); } Iterative (Single Sta ...

Identify isolated groups of zeros in a grid that do not border grid edges. Traverse connected components using BFS while tracking boundary collisions. #include <vector> #include <queue> #include <iostream> int main() { int rows, cols; std::cin >> cols >> rows; std::vector grid(rows, std::vector&lt ...

The problems in this set require careful handling of edge cases and efficient algorithms. Below are the solutions for all four tasks. T1: Holiday Plan Given constraints n ≤ 2.5 × 103, an O(n2) approach is feasible. We enumerate the middle two vertices B and C. For a valid pair (B, C), we pre‑compute the set of possible A (from B) and possible D ...

The UVA589 problem requires finding the optimal path to push a box to a target location. The optimization criteria have two levels: primarily minimizing the number of pushes, and secondarily minimizing the total number of moves when push counts are equal. Key Problem Constraints The primary objective is to minimize push operations, not walki ...

Floyd Algorithm for All-Pairs Shortest Path Implement Floyd's algorithm to compute shortest paths between all pairs of vertices in an undirected weighted graph. The graph is defined by vertices labeled from 1 to n and m edges with positive weights. For multiple queries, output the shotrest distance betwean two vertices or -1 if no path exists. ...

This problem involves a BFS simulation on an ice floor grid. The movement mechanics require sliding in a chosen direction until hitting an obstacle. The algorithm explores four directions from each position, continuing to slide until a wall is encountered, at which point the stopping position becomes a new node in the traversal. Key implementat ...