April Fools Day Contest 2020

5 problems from April Fools Day Contest 2020 (contest 1331), difficulty -. 1/5 solutions verified against sample I/O.

5 items

April Fools Day Contest 2020

April Fools | 5 problems | 1/5 verified | Difficulty - | 17m 57s

# Problem Rating Tags Accepted Time ✓
A Is it rated? *special 17,506 3m 12s
B Limericks *special, math, number-theory 7,160 3m 36s
D Again? *special, implementation 12,102 2m 40s
G Lingua Romana *special 594 5m 2s ✓
H It's showtime *special 649 3m 27s
Practice › Codeforces Solutions › April Fools Day Contest 2020 ›

CF 1331G - Lingua Romana

We are given a short program written in a heavily stylized “Roman-like” pseudocode language. The program reads a sequence of integers from standard input, and for each integer it computes a numeric function and prints either a formatted value or a special overflow message.
codeforces competitive-programming *special Jun 16, 2026
Practice › Codeforces Solutions › April Fools Day Contest 2020 ›

CF 1331D - Again?

We are given a single 7-character number written in a mixed numeral system. The first character is always the letter A, which should be interpreted as the value 10. The remaining six characters are digits from 0 to 9. Together, they form a base-11 number of fixed length 7.
codeforces competitive-programming *special implementation Jun 16, 2026
Practice › Codeforces Solutions › April Fools Day Contest 2020 ›

CF 1331H - It's showtime

The problem presents a single integer input that encodes two pieces of information. The integer can be decomposed as input = 1000 n + mod, where n is the number for which we want the double factorial and mod is the modulus to compute it under.
codeforces competitive-programming *special Jun 11, 2026
Practice › Codeforces Solutions › April Fools Day Contest 2020 ›

CF 1331B - Limericks

The problem asks us to compute a specific numeric property related to an integer input, denoted as a. While the problem statement is written in a poetic form, the underlying task is to find the number of integers less than a that are coprime to a.
codeforces competitive-programming *special math number-theory Jun 11, 2026
Practice › Codeforces Solutions › April Fools Day Contest 2020 ›

CF 1331A - Is it rated?

The solution does not successfully establish what Exercise 4.6.3.13 asks. The positive part is that the displayed constructions are now genuine star chains.
codeforces competitive-programming *special Jun 11, 2026