April Fools Day Contest

Solutions for April Fools Day Contest (contest 171). 8/8 problems verified against sample I/O. Difficulty range: 1200-2000.

8 items

April Fools Day Contest

Type: April Fools | Problems: 8 | Verified: 8/8 | Rating range: 1200-2000 | Time: 13m 15s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Mysterious numbers - 1	1200	*special, constructive-algorithms	1m 43s	✓
B	Star	1300	*special, combinatorics	2m 57s	✓
C	A Piece of Cake	2000	*special, implementation	1m 30s	✓
D	Broken checker	1300	*special, brute-force	1m 14s	✓
E	MYSTERIOUS LANGUAGE	2000	*special	1m 1s	✓
F	ucyhf	1600	*special, brute-force, implementation	1m 11s	✓
G	Mysterious numbers - 2	1600	*special	2m	✓
H	A polyline	1700	*special, implementation	1m 39s	✓

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CF 171A - Mysterious numbers - 1

This problem comes from an April Fools contest where the statement intentionally hides the real task. We are given two non-negative integers. The required operation is: 1. Reverse the decimal representation of the second number. 2. Add the result to the first number. 3.

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CF 171H - A polyline

The input contains two numbers. The first number, a, determines the order of a recursively constructed polyline. The second number, b, is an index along that polyline. The picture in the statement is the key.

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CF 171G - Mysterious numbers - 2

We are given three small positive integers, a1, a2, and a3, each ranging from 1 to 20. The problem asks us to compute a single integer as output based on these three numbers.

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CF 171F - ucyhf

We are asked to find a special number associated with a single integer input d, where d represents a divisor or parameter in a number-theoretic sequence.

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CF 171E - MYSTERIOUS LANGUAGE

This is one of Codeforces' classic "special" problems. Unlike ordinary algorithmic tasks, there is no meaningful input to process and no data structure or optimization challenge to solve. The contest provides access to a language called Secret through the custom test environment.

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CF 171D - Broken checker

This is one of the most unusual problems on Codeforces. The input is supposed to contain a single integer between 1 and 5. There are only five official test cases. The output must be a single integer between 1 and 3. The crucial detail is that there is no actual task to solve.

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CF 171B - Star

In this problem, we are asked to calculate the total number of cells in a star-shaped pattern drawn on a grid, given a number of layers. The input is a single integer a, representing the number of concentric layers in the star.

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CF 171C - A Piece of Cake

The input is a sequence of integers. The first number tells us how many additional integers follow. If the sequence is: then there are four values: 1, 2, 3, 4. The task itself is intentionally disguised by the strange statement.