Codeforces Round 1029 (Div. 3)

Solutions for Codeforces Round 1029 (Div. 3) (contest 2117). 3/8 problems verified against sample I/O. Difficulty range: 800-2500.

8 items

Codeforces Round 1029 (Div. 3)

Type: Div. 3 | Problems: 8 | Verified: 3/8 | Rating range: 800-2500 | Time: 17m 28s

Problem	Name	Rating	Tags	Solve Time	Verified
A	False Alarm	800	greedy, implementation	1m 12s	✓
B	Shrink	800	constructive-algorithms	1m 48s	✗
C	Cool Partition	1200	data-structures, greedy	1m 53s	✗
D	Retaliation	1200	binary-search, math, number-theory	1m 32s	✓
E	Lost Soul	1600	brute-force, greedy	4m 44s	✗
F	Wildflower	1800	combinatorics, dfs-and-similar, trees	3m 8s	✗
G	Omg Graph	1900	brute-force, dsu, graphs	1m 19s	✓
H	Incessant Rain	2500	data-structures, divide-and-conquer, sortings	1m 52s	✗

Practice › Codeforces Solutions › Codeforces Round 1029 (Div. 3) ›

CF 2117H - Incessant Rain

We are given an array of integers and a sequence of queries. Each query updates a single element of the array, and after the update, we are asked for the maximum integer $k$ such that some subarray contains a $k$-majority.

Practice › Codeforces Solutions › Codeforces Round 1029 (Div. 3) ›

CF 2117F - Wildflower

We are given a rooted tree where vertex 1 is the root, and every node must be assigned a value either 1 or 2. Once these values are fixed, every node computes a quantity defined as the sum of values in its rooted subtree, meaning the node itself plus all of its descendants.

Practice › Codeforces Solutions › Codeforces Round 1029 (Div. 3) ›

CF 2117E - Lost Soul

The repeated runtime errors you are seeing are all caused by misaligned assumptions about the input format. Let me go step by step. Looking at your input: The first line 5 is the number of test cases.

Practice › Codeforces Solutions › Codeforces Round 1029 (Div. 3) ›

CF 2117G - Omg Graph

We are working with a weighted undirected connected graph where we need to travel from node 1 to node n. Every path is allowed to revisit vertices and edges, so cycles are permitted.

Practice › Codeforces Solutions › Codeforces Round 1029 (Div. 3) ›

CF 2117C - Cool Partition

We are given an array of integers and need to divide it into contiguous segments. Each element must appear in exactly one segment. A partition is considered cool if every element in a segment also appears in the next segment, if there is one.

Practice › Codeforces Solutions › Codeforces Round 1029 (Div. 3) ›

CF 2117B - Shrink

The task is to construct a permutation of length $n$ that allows the maximum number of "shrink" operations. A shrink operation removes an element that is larger than its immediate neighbors.

Practice › Codeforces Solutions › Codeforces Round 1029 (Div. 3) ›

CF 2117D - Retaliation

We are given an array of positive integers, and the goal is to repeatedly apply one of two operations to reduce every element to zero. The first operation subtracts each element by its 1-based index, and the second subtracts each element by its "reverse index" (n minus i plus 1).

Practice › Codeforces Solutions › Codeforces Round 1029 (Div. 3) ›

CF 2117A - False Alarm

We are given a sequence of doors arranged in a line. Each door is either open or closed. Yousef starts before the first door and must move strictly from door 1 to door n in order.