Freaks City

Problem D - Take ABC 2 An efficient approach involves processing the string from the end to identify and count valid "ABC" sequences. #include <vector> #include <string> #include <iostream> using namespace std; void processString() { string input; cin >> input; vector<int> posA, posB, posC; ...

Introduction This is a challenging problem that combines segment tree merging with dynamic programming optimization. While it follows a relatively standard template, the overall difficulty level is high. Prerequisites: Dynamic programming, tree-based DP, segmant tree with dynamic node allocation, segment tree merging. Problem link: Click here D ...

House Robber I The classic house robber problem involves selecting houses to rob such that adjacent houses cannot both be robbed, maximizing total profit. For each house, there are two choices: rob it or skip it. The decision at each position aims to maximize accumulated wealth. State Defniition: wealth[i] represents the maximum money obtainabl ...

[CTS2024] The Gate of All Beings This is a constructive problem on tree traversal. Observation of large test cases shows the answer does not exceed 3. It is posssible to traverse the entire tree with paths of length at most 3. The answer is typically 0 or 1, except for small trees or star-shaped graphs. For small n (≤ 8), a brute-force search o ...

Dynamic programming solutions for contiguous subarray challenges typically analyze sequences where each element serves as the endpoint of potential subarrays. This approach efficiently leverages overlapping subproblems and optimal substructure properties. Maximum Subarray Sum Finding the largest sum of any contiguous subarray uses Kadane's algo ...

Directed Edge Orientation with Out-Degree ConstraintGiven an undirected graph, determine the number of ways to orient all edges such that every vertex has an out-degree of exactly 1. The result should be modulo 998244353.For such an orientation to exist, the number of edges must exactly equal the number of vertices, i.e., m = n. Furthermore, ev ...

Maximum Product of Splitted Binary Tree Given a binary tree with root node, remove exactly one edge to split the tree into two separate subtrees. The goal is to maximize the product of the sums of both resulting subtrees. Return the result modulo 10^9 + 7. Approach The key insight is that during a depth-first search that calculates subtree sums ...

To solve this problem, we scan every possible 2x2 submatrix in a n × m grid and check whether the four characters within it collectively contain at least one 'y', one 'o', and one 'u'. The order does not matter—only the presence of all three required characters. The algorithm iterates over all valid top-left corners of 2x2 blocks (from row 1 to ...

Problem Description Given a number triangle, where each number is placed above two numbers in the row below, find the maximum possible sum of a path starting from the top and moving to adjacent numbers on the row below until the base of the triangle is reached. For example, consider the following triangle: 7 3 8 8 1 0 2 7 4 4 4 5 2 6 ...

A player collects trading cards with n distinct types. Each draw yields card type i with probability pi. Duplicate cards convert to coins, where k coins can be exchanged for one missing card. The process continues until all card types are collected. Compute the expected number of draws required. Input Format First line: n (card types) and k (co ...