Codeforces Round 807 (Div. 2)

Solutions for Codeforces Round 807 (Div. 2) (contest 1705). 2/6 problems verified against sample I/O. Difficulty range: 800-2900.

6 items

Codeforces Round 807 (Div. 2)

Type: Div. 2 | Problems: 6 | Verified: 2/6 | Rating range: 800-2900 | Time: 13m 59s

Problem Name Rating Tags Solve Time Verified
A Mark the Photographer 800 greedy, sortings 1m 58s ✓
B Mark the Dust Sweeper 900 constructive-algorithms, greedy, implementation 2m 59s ✗
C Mark and His Unfinished Essay 1400 brute-force, implementation 2m 42s ✗
D Mark and Lightbulbs 1800 combinatorics, constructive-algorithms, greedy 1m 55s ✓
E Mark and Professor Koro 2300 binary-search, bitmasks, brute-force 1m 49s ✗
F Mark and the Online Exam 2900 bitmasks, constructive-algorithms, interactive 2m 36s ✗
Practice › Codeforces Solutions › Codeforces Round 807 (Div. 2) ›

CF 1705F - Mark and the Online Exam

We are asked to recover the answer key for an online true/false exam with $n$ questions. Each question has exactly one correct answer, either 'T' for true or 'F' for false.
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CF 1705E - Mark and Professor Koro

We are given a multiset of positive integers that changes over time. At any moment, we are allowed to take two equal values, remove both, and replace them with a single value that is one larger.
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CF 1705D - Mark and Lightbulbs

We are given a row of lightbulbs, each either on or off, represented as a binary string s. Mark wants to transform this initial configuration into a target configuration t by repeatedly toggling bulbs under a restricted operation: he can choose any bulb i that is not the first…
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CF 1705B - Mark the Dust Sweeper

We are given a row of rooms, each with some amount of dust. Mark wants to clean all rooms except the last one, using a special operation that moves one unit of dust from an earlier room to a later one, but only if all rooms in between are nonzero.
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CF 1705C - Mark and His Unfinished Essay

Two constructions are proposed for generating a random variable $X$ with a nontrivial distribution on $[-1,1]$. The first maps a single uniform deviate through a trigonometric transformation.
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CF 1705A - Mark the Photographer

We have a total of $2n$ people with known heights. Mark wants to arrange them into two rows of $n$ people each: a front row and a back row.
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