Codeforces Round 1012 (Div. 1)

7 problems from Codeforces Round 1012 (Div. 1) (contest 2089), difficulty 1700-3500. 1/7 solutions verified against sample I/O.

7 items

Codeforces Round 1012 (Div. 1)

Div. 1 | 7 problems | 1/7 verified | Difficulty 1700-3500 | 12m 42s

#	Problem	Rating	Tags	Accepted	Time	✓
A	Simple Permutation	1700	constructive-algorithms, number-theory	7,189	1m 24s	✓
B1	Canteen (Easy Version)	1900	binary-search, data-structures, flows	3,232	1m 36s
B2	Canteen (Hard Version)	2300	binary-search, data-structures, dp	1,280	2m 35s
C1	Key of Like (Easy Version)	2200	dp, games, math	1,458	1m 50s
C2	Key of Like (Hard Version)	3100	dp, math, probabilities	259	2m 2s
D	Conditional Operators	3200	constructive-algorithms	188	1m 31s
E	Black Cat Collapse	3500		127	1m 44s

Practice › Codeforces Solutions › Codeforces Round 1012 (Div. 1) ›

CF 2089E - Black Cat Collapse

The problem describes a rooted tree with nodes labeled from $1$ to $n$, where node $1$ is the root. Liki and Sasami perform explorations over several days, and each exploration destroys the chosen node and its entire subtree.

Practice › Codeforces Solutions › Codeforces Round 1012 (Div. 1) ›

CF 2089D - Conditional Operators

We are given a binary string of length 2n+1. The goal is to insert exactly n conditional operators ?: between the characters to form a valid C++-style expression, optionally adding parentheses, and determine if the final expression can evaluate to 1.

Practice › Codeforces Solutions › Codeforces Round 1012 (Div. 1) ›

CF 2089C2 - Key of Like (Hard Version)

We are given a game where n members take turns trying to open l locks using a set of l + k keys. Among these keys, exactly l are genuine and each opens exactly one lock, while the remaining k keys are fake.

Practice › Codeforces Solutions › Codeforces Round 1012 (Div. 1) ›

CF 2089C1 - Key of Like (Easy Version)

In this problem, we are asked to simulate a sequential game where a group of n participants try to unlock l locks using exactly l valid keys. Each participant takes one turn at a time in a fixed cyclic order.

Practice › Codeforces Solutions › Codeforces Round 1012 (Div. 1) ›

CF 2089B2 - Canteen (Hard Version)

Working

Practice › Codeforces Solutions › Codeforces Round 1012 (Div. 1) ›

CF 2089B1 - Canteen (Easy Version)

We are given two arrays of equal length. You can think of each index as a station that holds two piles of units: one pile from array a and one pile from array b. The process runs in synchronized rounds, and each round has a fixed structure.

Practice › Codeforces Solutions › Codeforces Round 1012 (Div. 1) ›

CF 2089A - Simple Permutation

We are asked to construct a permutation of integers from 1 to $n$ with a special property. For each prefix of the permutation, we compute the average of the first $i$ elements, take its ceiling, and call that $ci$.