Codeforces Round 1053 (Div. 2)

Solutions for Codeforces Round 1053 (Div. 2) (contest 2151). 0/8 problems verified against sample I/O. Difficulty range: 800-2800.

8 items

Codeforces Round 1053 (Div. 2)

Type: Div. 2 | Problems: 8 | Verified: 0/8 | Rating range: 800-2800 | Time: 12m 29s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Incremental Subarray	800	math, strings	2m 9s	✗
B	Incremental Path	1300	implementation	1m 32s	✗
C	Incremental Stay	1400	greedy, implementation, math	1m 26s	✗
D	Grid Counting	1700	combinatorics	1m 39s	✗
E	Limited Edition Shop	2100	data-structures, dp, games	1m 26s	✗
F	Attraction Theory	2700	combinatorics, dp	1m 25s	✗
G1	Hidden Single (Version 1)	2600	binary-search, divide-and-conquer, interactive	1m 30s	✗
G2	Hidden Single (Version 2)	2800	binary-search, divide-and-conquer, interactive	1m 22s	✗

Practice › Codeforces Solutions › Codeforces Round 1053 (Div. 2) ›

CF 2151G1 - Hidden Single (Version 1)

We are given a hidden array of length 2n-1 where each number from 1 to n appears exactly twice except for one number, which appears exactly once. Our goal is to determine which number appears only once. We do not need to find its position, only the value.

Practice › Codeforces Solutions › Codeforces Round 1053 (Div. 2) ›

CF 2151G2 - Hidden Single (Version 2)

We are given a hidden sequence of length $2n-1$ that contains every number from $1$ to $n$ exactly twice, except for one special value that appears only once. So the multiset looks like a perfect pairing structure with a single unpaired element. We cannot see the array directly.

Practice › Codeforces Solutions › Codeforces Round 1053 (Div. 2) ›

CF 2151F - Attraction Theory

We are given a one-dimensional line with $n$ people initially at positions $1$ through $n$, and each position $i$ has a value $ai$.

Practice › Codeforces Solutions › Codeforces Round 1053 (Div. 2) ›

CF 2151D - Grid Counting

We are given an $n times n$ grid and we must choose a set of black cells. The choice is constrained by three independent-looking counting rules. The first rule fixes how many black cells appear in each row. Row $k$ must contain exactly $ak$ chosen cells.

Practice › Codeforces Solutions › Codeforces Round 1053 (Div. 2) ›

CF 2151E - Limited Edition Shop

We are asked to simulate a limited-edition shop where Alice and Bob take turns picking items, but with a twist: we do not control who goes first or in which order they enter. Each item has a value according to us, and Alice and Bob each have a personal ranking of the items.

Practice › Codeforces Solutions › Codeforces Round 1053 (Div. 2) ›

CF 2151A - Incremental Subarray

Let $m = 2^e$ and consider the modified middle-square sequence defined by Coveyou: $X0 text{ given}, qquad X{n+1} = operatorname{middle}(Xn^2 + 2^{e-1} Xn), eqno(4)$ where the function $operatorname{middle}(cdot)$ extracts the middle $2e$ bits of the argument in double precision.

Practice › Codeforces Solutions › Codeforces Round 1053 (Div. 2) ›

CF 2151B - Incremental Path

We are given a virtual strip with cells numbered from 1 to $10^9$, where some cells are initially black and the rest are white. Multiple people start from cell 1, and each executes a prefix of a command string composed of two instructions.

Practice › Codeforces Solutions › Codeforces Round 1053 (Div. 2) ›

CF 2151C - Incremental Stay

We are given a sequence of 2n timestamps representing moments when visitors passed through a single museum door. Each timestamp corresponds either to an entrance or an exit, but the sensor cannot distinguish which.