Codeforces Round 1004 (Div. 2)

Solutions for Codeforces Round 1004 (Div. 2) (contest 2067). 3/7 problems verified against sample I/O. Difficulty range: 800-3300.

7 items

Codeforces Round 1004 (Div. 2)

Type: Div. 2 | Problems: 7 | Verified: 3/7 | Rating range: 800-3300 | Time: 13m 28s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Adjacent Digit Sums	800	brute-force, constructive-algorithms, math	1m 41s	✓
B	Two Large Bags	1200	brute-force, dp, greedy	2m 16s	✓
C	Devyatkino	1500	brute-force, dfs-and-similar, greedy	1m 38s	✓
D	Object Identification	1400	constructive-algorithms, graphs, interactive	1m 52s	✗
E	White Magic	1900	constructive-algorithms, greedy, implementation	2m 32s	✗
F	Bitwise Slides	2300	bitmasks, data-structures, dp	2m	✗
G	Tropical Season	3300	data-structures	1m 29s	✗

Practice › Codeforces Solutions › Codeforces Round 1004 (Div. 2) ›

CF 2067F - Bitwise Slides

We are given an array of integers, and three variables P, Q, R initially set to zero. For each element of the array, we must choose to XOR it into exactly one of the three variables. The main restriction is that at every step, the three variables cannot all be distinct.

Practice › Codeforces Solutions › Codeforces Round 1004 (Div. 2) ›

CF 2067G - Tropical Season

We are given a collection of barrels, each containing some amount of water, and one of them has a tiny amount of poison. The poison adds an imperceptible 0.179 kilograms to the barrel's weight.

Practice › Codeforces Solutions › Codeforces Round 1004 (Div. 2) ›

CF 2067E - White Magic

Working

Practice › Codeforces Solutions › Codeforces Round 1004 (Div. 2) ›

CF 2067B - Two Large Bags

We start with an array of n numbers in the first bag and an empty second bag. Since the final bags must be identical, each bag must end up containing exactly n/2 numbers. There are only two allowed operations.

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CF 2067D - Object Identification

We are given an array x of length n with integers from 1 to n, and a hidden array y of the same length. Each pair (xi, yi) is unique and xi ≠ yi.

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CF 2067A - Adjacent Digit Sums

We are asked to determine whether there exists an integer n such that the sum of its digits equals a given number x, and the sum of the digits of n + 1 equals another given number y.

Practice › Codeforces Solutions › Codeforces Round 1004 (Div. 2) ›

CF 2067C - Devyatkino

The problem gives us a positive integer n, and allows us to perform an operation where we add any number that consists entirely of the digit 9 repeated one or more times. Our goal is to make n contain at least one digit 7 using the minimum number of such operations.