Educational Codeforces Round 176 (Rated for Div. 2)

6 problems from Educational Codeforces Round 176 (Rated for Div. 2) (contest 2075), difficulty 800-3000. 1/6 solutions verified against sample I/O.

6 items

Educational Codeforces Round 176 (Rated for Div. 2)

Div. 2 | 6 problems | 1/6 verified | Difficulty 800-3000 | 9m 36s

#	Problem	Rating	Tags	Accepted	Time	✓
A	To Zero	800	greedy, math	27,905	1m 46s
B	Array Recoloring	1300	constructive-algorithms, greedy	18,827	1m 17s	✓
C	Two Colors	1500	binary-search, combinatorics, math	14,356	1m 49s
D	Equalization	2000	bitmasks, brute-force, dp	5,825	1m 36s
E	XOR Matrix	2500	bitmasks, combinatorics, dp	1,184	1m 34s
F	Beautiful Sequence Returns	3000	binary-search, brute-force, data-structures	520	1m 34s

Practice › Codeforces Solutions › Educational Codeforces Round 176 (Rated for Div. 2) ›

CF 2075F - Beautiful Sequence Returns

We are given an array and we want to extract a subsequence that satisfies two structural constraints. Every element except the first must have some smaller element somewhere to its left inside the subsequence.

Practice › Codeforces Solutions › Educational Codeforces Round 176 (Rated for Div. 2) ›

CF 2075E - XOR Matrix

We are asked to count the number of ways to construct two arrays, a of length n and b of length m, such that the XOR matrix formed by X[i][j] = a[i] XOR b[j] contains at most two distinct values.

Practice › Codeforces Solutions › Educational Codeforces Round 176 (Rated for Div. 2) ›

CF 2075D - Equalization

We are given two non-negative integers, $x$ and $y$, and we want to make them equal by repeatedly performing a division operation. The operation allows us to choose a positive integer $k$ and divide either $x$ or $y$ by $2^k$, rounding down to the nearest integer.

Practice › Codeforces Solutions › Educational Codeforces Round 176 (Rated for Div. 2) ›

CF 2075C - Two Colors

We are asked to count the number of ways to paint a fence of n consecutive planks using exactly two colors such that each color is used in a contiguous block, and the available quantity of each paint is limited.

Practice › Codeforces Solutions › Educational Codeforces Round 176 (Rated for Div. 2) ›

CF 2075A - To Zero

We are asked to reduce a number n to zero using a series of subtractions constrained by parity. Each operation allows us to subtract any number between 1 and k, but if the current n is even, we must subtract an even number, and if n is odd, we must subtract an odd number.

Practice › Codeforces Solutions › Educational Codeforces Round 176 (Rated for Div. 2) ›

CF 2075B - Array Recoloring

We are given an array of integers where each element is initially colored red. The goal is to select exactly k elements to paint blue. After this initial selection, we repeatedly paint red elements that are adjacent to a blue element until the entire array is blue.