Freaks City

Core Idea of Greedy Algorithms The essence of a greedy strategy is to build a globally optimal solution by repeatedly making locally optimal choices. The typical workflow involves: Breaking the problem into smaller subproblems. Determining a suitable greedy criterion. Obtaining the best posssible choice for each subproblem. Aggregating these l ...

Problem A Each meal costs 800 yen. For every 15 meals purchased, a refund of 200 yen is issued. Given $ x $, the total number of meals consumed, compute the net expenditure. The formula is: $$ 800x - \left\lfloor \frac{x}{15} \right\rfloor \cdot 200 $$ Problem B After $ N $ workouts, where initial strength is 1 and each $ i $-th workout multipl ...

Problem D: Journey to Un'Goro For small sequence lengths (n ≤ 20), iterate through all possible binary strings of length n. For each string, compute the prefix sum of red characters ('r' represented as 1, 'b' as 0). Count the number of subarrays where the sum of reds is odd. Track the maximum count and collect all configurations achieving it. F ...

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 ...

A. Points in Segments An approach with a time complextiy of $ \mathcal{O}(n \times m) $ works well for small data ranges. The idea is to mark each point within the given intervals and then count how many points are not marked. #include <bits/stdc++.h> #define int long long using namespace std; signed main() { ios::sync_with_stdio(f ...

A - The Number of Even Pairs Given (n) even numbers and (m) odd numbers, count the number of ways to choose two distinct numbers such that their sum is even. A sum is even only if both numbers have the same parity. The number of ways to pick two evens is (\binom{n}{2} = n(n-1)/2), and for two odds its (\binom{m}{2} = m(m-1)/2). The total is the ...

Problem Source This problem is from the SQL section of Niuke's Big Company Real Interview Questions, specifically scenario 02: User Growth (Baidu Information Flow), question SQL164: Calculate the next-day retention rate of new users for each day in November 2021. Shifting from Macro-to-Micro to Micro-to-Macro Previous chapters emphasized a top- ...

Six problems drawn from a competitive programming rating competition are analysed below. Every solution is accompanied by both C++ and Python implementations. Keep in mind that Python code may run slower and care should be taken with complexity constants. Problem 1 – Output a Digit Different from the Product Given two integers a and b, print an ...

It is clear that S represents the initial magic value, k is the number of selected items, and x is given in the problem. Noting that x is large but k and n are small, we can define a state that tracks the i-th item, the number of selected items j, and the sum modulo k as l. The goal is to maximize the initial magic value, as higher values reduc ...

A. Incorrect Subtraction Simulate the process of subtracting 1 from the last digit of a number for k times. If the last digit is 0, remove it instead. #include <bits/stdc++.h> #define endl '\n' #define int long long using namespace std; const int N = 2e3 + 10, mod = 1e9 +7; typedef pair<int,int> PII; int n,m,t,k; vector<int& ...