Educational Codeforces Round 174 (Rated for Div. 2)

6 problems from Educational Codeforces Round 174 (Rated for Div. 2) (contest 2069), difficulty 800-2800. 2/6 solutions verified against sample I/O.

6 items

Educational Codeforces Round 174 (Rated for Div. 2)

Div. 2 | 6 problems | 2/6 verified | Difficulty 800-2800 | 10m 15s

#	Problem	Rating	Tags	Accepted	Time	✓
A	Was there an Array?	800	graph-matchings, greedy	26,547	1m 28s	✓
B	Set of Strangers	1200	greedy, matrices	18,806	1m 33s
C	Beautiful Sequence	1500	combinatorics, dp, greedy	14,813	1m 38s
D	Palindrome Shuffle	1800	binary-search, greedy, hashing	7,047	1m 36s	✓
E	A, B, AB and BA	2300	constructive-algorithms, greedy, sortings	1,906	2m 12s
F	Graph Inclusion	2800	data-structures, dfs-and-similar, divide-and-conquer	789	1m 48s

Practice › Codeforces Solutions › Educational Codeforces Round 174 (Rated for Div. 2) ›

CF 2069E - A, B, AB and BA

We are given a string consisting only of A and B. We must partition the entire string into pieces of length one or two. Single-character pieces are allowed to be "A" or "B". Two-character pieces are allowed only to be "AB" or "BA". Pieces "AA" and "BB" are forbidden.

Practice › Codeforces Solutions › Educational Codeforces Round 174 (Rated for Div. 2) ›

CF 2069F - Graph Inclusion

We are given two undirected graphs, $A$ and $B$, on the same set of $n$ vertices. Initially, both graphs have no edges. Queries arrive one by one; each query either toggles an edge in $A$ or $B$.

Practice › Codeforces Solutions › Educational Codeforces Round 174 (Rated for Div. 2) ›

CF 2069D - Palindrome Shuffle

We are given a string of even length, consisting only of lowercase letters. The allowed operation is to select any contiguous substring of the string and shuffle its characters arbitrarily.

Practice › Codeforces Solutions › Educational Codeforces Round 174 (Rated for Div. 2) ›

CF 2069C - Beautiful Sequence

We are asked to count the number of "beautiful" subsequences in an array where every element is either 1, 2, or 3.

Practice › Codeforces Solutions › Educational Codeforces Round 174 (Rated for Div. 2) ›

CF 2069B - Set of Strangers

We are given a rectangular grid of size $n times m$ where each cell has a color represented by an integer. We can perform painting operations where in a single step we choose a set of cells that are strangers-that is, no two of them share a side-and all have the same color…

Practice › Codeforces Solutions › Educational Codeforces Round 174 (Rated for Div. 2) ›

CF 2069A - Was there an Array?

We are given an array of 0s and 1s representing a “local equality” pattern for some unknown array of integers.