Codeforces Round 1074 (Div. 4)

8 problems from Codeforces Round 1074 (Div. 4) (contest 2185), difficulty 800-2500. 4/8 solutions verified against sample I/O.

8 items

Codeforces Round 1074 (Div. 4)

Div. 4 | 8 problems | 4/8 verified | Difficulty 800-2500 | 19m 7s

# Problem Rating Tags Accepted Time ✓
A Perfect Root 800 constructive-algorithms, math 43,030 1m 48s
B Prefix Max 800 greedy 40,649 1m 45s ✓
C Shifted MEX 900 implementation, sortings 28,953 2m 5s
D OutOfMemoryError 1100 data-structures, implementation, math 20,655 2m 34s ✓
E The Robotic Rush 1500 binary-search, greedy, implementation 10,200 2m 46s ✓
F BattleCows 1700 data-structures, divide-and-conquer, implementation 4,999 3m 10s ✓
G Mixing MEXes 1800 data-structures, implementation, math 3,300 2m 3s
H BattleCows 2 2500 binary-search, brute-force, data-structures 679 2m 56s
Practice › Codeforces Solutions › Codeforces Round 1074 (Div. 4) ›

CF 2185H - BattleCows 2

The tournament has a surprisingly simple structure once we stop thinking about individual matches. Whenever a cow survives a match, its new skill becomes the sum of the two participants.
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CF 2185G - Mixing MEXes

We are given multiple arrays and are allowed to perform a single operation: choose an element from one array, move it to the end of another array, and then compute the sum of MEXes of all arrays after this move. The task is to sum the values of all possible such operations.
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CF 2185F - BattleCows

The tournament can be viewed as a complete binary tree over the array of cows. Each leaf is a single cow. Every internal node represents a contiguous segment of cows. The skill of a node is the XOR of all values inside that segment.
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CF 2185E - The Robotic Rush

Every robot receives exactly the same sequence of moves. After the first instruction, all robots shift by the same displacement. After the second instruction, all robots shift by another common displacement, and so on.
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CF 2185D - OutOfMemoryError

We start with an array and a sequence of update operations. Each operation adds some value to one position. The unusual part is the crash rule. After every update, if any element of the current array becomes larger than h, the computer immediately crashes.
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CF 2185C - Shifted MEX

We are given an array of integers, which may include negative numbers. The task allows us to pick a single integer shift x and add it to every element of the array. After performing this shift, we want to maximize the MEX of the array.
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CF 2185A - Perfect Root

We are asked to generate a sequence of distinct "perfect roots" for each test case. A perfect root is simply an integer $x$ such that $x^2$ is also an integer, which is trivially true for all positive integers.
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CF 2185B - Prefix Max

We are given an array. For every position, we look at the prefix ending there and take the maximum value seen so far. The score of the array is the sum of all those prefix maxima. We may swap any two elements at most once, or choose not to swap at all.
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