Codeforces Round 561 (Div. 2)

Solutions for Codeforces Round 561 (Div. 2) (contest 1166). 4/6 problems verified against sample I/O. Difficulty range: 900-2400.

6 items

Codeforces Round 561 (Div. 2)

Type: Div. 2 | Problems: 6 | Verified: 4/6 | Rating range: 900-2400 | Time: 12m 27s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Silent Classroom	900	combinatorics, greedy	1m 43s	✓
B	All the Vowels Please	1100	constructive-algorithms, math, number-theory	1m 31s	✓
C	A Tale of Two Lands	1500	binary-search, sortings, two-pointers	1m 27s	✓
D	Cute Sequences	2200	binary-search, brute-force, greedy	2m 48s	✗
E	The LCMs Must be Large	2100	bitmasks, brute-force, constructive-algorithms	1m 29s	✓
F	Vicky's Delivery Service	2400	data-structures, dsu, graphs	3m 29s	✗

Practice › Codeforces Solutions › Codeforces Round 561 (Div. 2) ›

CF 1166F - Vicky's Delivery Service

The task describes a growing undirected graph where each edge also carries a color. Edges only ever get added, never removed. Interleaved with these updates are connectivity queries, but connectivity is not defined in the usual sense of arbitrary walks.

Practice › Codeforces Solutions › Codeforces Round 561 (Div. 2) ›

CF 1166D - Cute Sequences

We are given a starting value a, an ending value b, and a parameter m. We need to decide whether we can construct a sequence of positive integers that begins at a, ends at b, and grows in a very specific cumulative way.

Practice › Codeforces Solutions › Codeforces Round 561 (Div. 2) ›

CF 1166A - Silent Classroom

We are given a list of student names and we are allowed to split these students into two classrooms. Every student must go to exactly one of the two rooms, and either room may end up empty.

Practice › Codeforces Solutions › Codeforces Round 561 (Div. 2) ›

CF 1166E - The LCMs Must be Large

We are given a set of stores, each selling an unknown positive integer, and a record of Dora's purchases over several days. On each day, she bought integers from some stores, while her rival, Swiper, bought from the remaining stores.

Practice › Codeforces Solutions › Codeforces Round 561 (Div. 2) ›

CF 1166B - All the Vowels Please

We are trying to construct a string of length $k$ that can be rearranged into a rectangular grid with $n$ rows and $m$ columns such that every row and every column contains all five vowels: a, e, i, o, u at least once.

Practice › Codeforces Solutions › Codeforces Round 561 (Div. 2) ›

CF 1166C - A Tale of Two Lands

We are given a set of integers representing potential values for two historical markers, $x$ and $y$. For each candidate pair of distinct integers $(x, y)$, we compute two intervals on the number line.