Nebius Welcome Round (Div. 1 + Div. 2)

8 problems from Nebius Welcome Round (Div. 1 + Div. 2) (contest 1804), difficulty 800-3500. 5/8 solutions verified against sample I/O.

8 items

Nebius Welcome Round (Div. 1 + Div. 2)

Div. 1+2 | 8 problems | 5/8 verified | Difficulty 800-3500 | 26m 58s

# Problem Rating Tags Accepted Time ✓
A Lame King 800 greedy, math 18,664 3m 40s ✓
B Vaccination 1000 greedy, implementation 15,621 2m 25s ✓
C Pull Your Luck 1500 brute-force, greedy, math 13,831 1m 41s ✓
D Accommodation 2000 brute-force, dp, greedy 5,267 1m 43s ✓
E Routing 2400 bitmasks, brute-force, dfs-and-similar 1,706 2m 51s
F Approximate Diameter 2700 binary-search, divide-and-conquer, graphs 1,175 3m 47s
G Flow Control 3500 data-structures, dsu, implementation 237 1m 20s ✓
H Code Lock 3300 bitmasks, dp 245 9m 31s
Practice › Codeforces Solutions › Nebius Welcome Round (Div. 1 + Div. 2) ›

CF 1804H - Code Lock

We are given a circular dial with $k$ positions. Each position is labeled with a distinct letter from the first $k$ letters of the alphabet. We are allowed to permute which letter sits at which position before starting.
codeforces competitive-programming bitmasks dp Jun 15, 2026
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CF 1804F - Approximate Diameter

We are given a connected, undirected graph with unit-length edges. The key quantity of interest is the graph diameter, which is the largest shortest-path distance between any pair of vertices.
codeforces competitive-programming binary-search divide-and-conquer graphs shortest-paths Jun 15, 2026
Practice › Codeforces Solutions › Nebius Welcome Round (Div. 1 + Div. 2) ›

CF 1804E - Routing

We are given an undirected, connected graph with up to 20 vertices. Each vertex represents a server, and edges represent direct bidirectional communication links. For every server $u$, we must choose exactly one adjacent vertex $a(u)$.
codeforces competitive-programming bitmasks brute-force dfs-and-similar dp graphs Jun 15, 2026
Practice › Codeforces Solutions › Nebius Welcome Round (Div. 1 + Div. 2) ›

CF 1804G - Flow Control

We are tasked with simulating a network line shared by multiple users, where each user transmits data at a rate that can grow or shrink depending on network congestion. Each user has a start time, end time, and initial data rate.
codeforces competitive-programming data-structures dsu implementation Jun 9, 2026
Practice › Codeforces Solutions › Nebius Welcome Round (Div. 1 + Div. 2) ›

CF 1804A - Lame King

A king starts at the origin of a grid and wants to reach a target cell (a, b). Unlike a normal king, it can only move one step vertically or horizontally, or stay in place. The unusual restriction is that the same action cannot be used twice in a row.
codeforces competitive-programming greedy math Jun 9, 2026
Practice › Codeforces Solutions › Nebius Welcome Round (Div. 1 + Div. 2) ›

CF 1804D - Accommodation

We are given a grid of size $n times m$ where each cell represents a window in a high-rise building. Each cell is either lit or dark. The building is structured in floors, and each floor is an independent row of the grid.
codeforces competitive-programming brute-force dp greedy implementation Jun 9, 2026
Practice › Codeforces Solutions › Nebius Welcome Round (Div. 1 + Div. 2) ›

CF 1804B - Vaccination

We are given a sorted list of arrival times of patients. Each patient arrives at a specific moment and is willing to wait for a limited number of time units, meaning there is a window during which they can be vaccinated.
codeforces competitive-programming greedy implementation Jun 9, 2026
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CF 1804C - Pull Your Luck

We have a roulette wheel with n sectors numbered from 0 to n-1. The wheel starts with an arrow pointing at sector x, and we can spin it by pulling a handle with an integer force f between 1 and p.
codeforces competitive-programming brute-force greedy math number-theory Jun 9, 2026