Codeforces Round 988 (Div. 3)

7 problems from Codeforces Round 988 (Div. 3) (contest 2037), difficulty 800-2100. 2/7 solutions verified against sample I/O.

7 items

Codeforces Round 988 (Div. 3)

Div. 3 | 7 problems | 2/7 verified | Difficulty 800-2100 | 16m 45s

#	Problem	Rating	Tags	Accepted	Time	✓
A	Twice	800	implementation	35,685	2m 19s	✓
B	Intercepted Inputs	800	brute-force, implementation	25,535	2m 8s
C	Superultra's Favorite Permutation	1000	constructive-algorithms, greedy, math	25,525	2m 20s
D	Sharky Surfing	1300	data-structures, greedy, two-pointers	14,741	2m 16s
E	Kachina's Favorite Binary String	1600	dp, greedy, interactive	7,371	2m 25s
F	Ardent Flames	2100	binary-search, data-structures, math	2,968	1m 40s	✓
G	Natlan Exploring	2000	bitmasks, combinatorics, data-structures	3,730	3m 37s

Practice › Codeforces Solutions › Codeforces Round 988 (Div. 3) ›

CF 2037G - Natlan Exploring

We are asked to count the number of distinct paths from the first city to the last city in a region of Natlan, where each city has an attractiveness value. The paths follow a simple rule: from city $i$ you can travel to city $j$ if $i < j$ and $gcd(ai, aj) neq 1$.

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CF 2037E - Kachina's Favorite Binary String

We are tasked with reconstructing a hidden binary string of length $n$ by querying a function $f(l, r)$, which counts the number of subsequences "01" in the substring from index $l$ to $r$. A subsequence is any selection of characters maintaining the original order.

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CF 2037D - Sharky Surfing

We are asked to model a surfboard journey along a one-dimensional path from position 1 to position $L$. Mualani starts with jump power 1, which allows her to move from her current position $x$ to any position in $[x, x+k]$, where $k$ is her current jump power.

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CF 2037F - Ardent Flames

We are given a line of enemies, each with a fixed health and a fixed position. Xilonen can attack from a single chosen position p, and each attack reduces an enemy’s health by m - The first key observation is that the damage from each attack decreases linearly with distance.

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CF 2037C - Superultra's Favorite Permutation

We are asked to construct a permutation of numbers from 1 to n such that the sum of every pair of consecutive numbers is composite. In other words, for a permutation p of length n, every p[i] + p[i+1] must not be a prime. If no such permutation exists, we return -1.

Practice › Codeforces Solutions › Codeforces Round 988 (Div. 3) ›

CF 2037A - Twice

We are given a small array of integers. Kinich can score points by repeatedly selecting two distinct indices containing equal values, with the restriction that each index can be used at most once. The task is to determine the maximum number of such pairings for each test case.

Practice › Codeforces Solutions › Codeforces Round 988 (Div. 3) ›

CF 2037B - Intercepted Inputs

The failure you show is not enough to diagnose the algorithm itself. Let's trace what happened: The input contains 5 test cases: The program produced only: instead of: This means the code successfully processed the first test case and then terminated before handling the…