Freaks City

Competition Details Duration: 3 hours Start Time: 2026/1/30 8:00 End Time: 2026/1/30 11:00 Difficulty Level: High Final Score: 340 Lost Points: 60 Problem Set Problem 1: Element Removal Sum Description Given a sequence of integers A of length N and an integer M, determine if it's possible to remove exactly one element from A such that the ...

Swapping Nodes in Pairs Problem: Given a linked list, swap every two adjacent nodes and return the modified list. You must not modify the values in the nodes, only the nodes themselves. The key approach involves careful pointer manipulation and the use of a temporray node to preserve references. We'll use a dummy node to simplify the edge ca ...

To compute the sum of all left leaf nodes in a binary tree, implement a recursive traversal that identifies nodes where the left child exists and has no children. When such a node is found, accuumlate its value. A helper function using reference accumulation: void accumulateLeftLeafSum(TreeNode* root, int& total) { if (!root) return; ...

Sorting Algorithms Quick Sort (Manual Implementation) #include <bits/stdc++.h> using namespace std; typedef long long ll; const int MAXN = 100010; ll arr[MAXN]; int n; void quickPartition(int left, int right) { if (left >= right) return; int pivotIdx = (left + right) / 2; ll pivotVal = arr[pivotIdx]; int i = left ...

Problem A: Array Segment Reversal Given an array of integers from 1 to n, reverse a specified segment between indices l and r. #include <iostream> #include <algorithm> using namespace std; int main() { int n, l, r; cin >> n >> l >> r; int arr[n+1]; for(int i=1; i<=n; i++) arr[i] = i; reverse ...

Problem Statement Given an integer \(M\), for any integer set \(S\), the "verification value" is defined as follows: From the set \(S\), extract \(M\) pairs of numbers (i.e., \(2M\) numbers, without reusing any element from the set; if there aren't enough numbers for \(M\) pairs, take as many as possible). The verification value is th ...

A - Three Pairwise Maximums Given three pairwise maximum values, determine if they can be derived from three positive integers. The solutoin involves sorting the input values and verifying consistency conditions. #include <iostream> #include <algorithm> using namespace std; void solve() { int nums[3]; cin >> nums[0] & ...

A. Omkar and Password Given a sequence of integres, we can merge adjacent disitnct elements into their sum. The goal is to minimize the final sequence length. If all elements are equal, no merges are possible and the result is the original length. Otherwise, we can always reduce the sequence to a single element by repeatedly merging with the ma ...

Problem Statement Write a function that calculates the quotient of two integers dividend and divisor without using the multiplication (*), division (/), or modulo (%) operators. The result should be truncated toward zero (e.g., truncate(8.345) = 8, truncate(-2.7335) = -2). Assume the environment only supports 32-bit signed inteegers, ranging fr ...

Problem Definition Given a string s containing only the characters (, ), {, }, [, and ], determine if the input string is valid. An input string is valid if: Open brackets must be closed by the same type of brackets. Open brackets must be closed in the correct order. Every close bracket has a corresponding open bracket of the same type. Examp ...