Codeforces Round 723 (Div. 2)

Solutions for Codeforces Round 723 (Div. 2) (contest 1526). 3/7 problems verified against sample I/O. Difficulty range: 800-3000.

7 items

Codeforces Round 723 (Div. 2)

Type: Div. 2 | Problems: 7 | Verified: 3/7 | Rating range: 800-3000 | Time: 14m 55s

Problem Name Rating Tags Solve Time Verified
A Mean Inequality 800 constructive-algorithms, sortings 2m 46s ✗
B I Hate 1111 1400 dp, math, number-theory 2m 3s ✓
C1 Potions (Easy Version) 1500 brute-force, data-structures, dp 1m 43s ✓
C2 Potions (Hard Version) 1600 data-structures, greedy 1m 17s ✗
D Kill Anton 2200 brute-force, constructive-algorithms, data-structures 2m 44s ✗
E Oolimry and Suffix Array 2400 combinatorics, constructive-algorithms, math 2m ✓
F Median Queries 3000 constructive-algorithms, interactive, probabilities 2m 22s ✗
Practice › Codeforces Solutions › Codeforces Round 723 (Div. 2) ›

CF 1526F - Median Queries

We are given a hidden permutation of the numbers from 1 to n. The permutation is fixed, but we never see it directly. Instead, we can only interact with it through a query on three indices.
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CF 1526D - Kill Anton

We are asked to take a string composed only of the characters "A", "N", "T", and "O" and find a permutation of it that maximizes the number of adjacent swaps required to revert it back to the original string.
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CF 1526E - Oolimry and Suffix Array

We are given a permutation representing the suffix array of some unknown string of length $n$ over an alphabet of size $k$. Each element $si$ of this array tells us which starting index corresponds to the $i$-th lexicographically smallest suffix.
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CF 1526C2 - Potions (Hard Version)

We are walking along a row of potions, starting at the first and moving to the last. Each potion has a value: positive values increase your health, negative values decrease it. At each potion, you can choose to drink it or skip it, but your health must never drop below zero.
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CF 1526A - Mean Inequality

Let a multiplication algorithm be called online if it produces the $(k+1)$st output bit of the product $uv$, starting from the least significant bit, only after reading the first $k+1$ input bits of each operand, also from least significant to most significant.
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CF 1526B - I Hate 1111

Every allowed number has a very special form: $$11, 111, 1111, 11111,dots$$ For each query, we are given a target value $x$, and we must determine whether it can be represented as a sum of these numbers, with unlimited reuse of each value.
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CF 1526C1 - Potions (Easy Version)

We have a sequence of potions lined up, each changing our health by some integer value, which can be positive or negative. We start with zero health and move from the first potion to the last.
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