Codentines Day

15 problems from Codentines Day (contest 104974), difficulty -. 3/15 solutions verified against sample I/O.

15 items

Codentines Day

Special | 15 problems | 3/15 verified | Difficulty - | 22m 19s

#	Problem	Rating	Tags	Accepted	Time	✓
A	Happy Valentine's Day				1m 12s
B	Arcade Game				1m 23s
C	Museum Visit				2m 21s
D	Traffic Lights				1m 9s
E	Intern Florist				49s	✓
F	Painting a Picture				1m 46s
G	Truecaller				1m 20s
H	Chocolate Messages				1m 2s	✓
I	Collin-Count				1m 27s
J	Bouquet of Flowers				1m 18s
K	Chocolate Tree				1m 35s
L	Gifts				1m 26s
M	Friend Management				1m 51s
N	Memory Problems				2m 36s
O	Gift Battle				1m 4s	✓

Practice › Codeforces Solutions › Codentines Day ›

CF 104974C - Museum Visit

We are working with a tree of rooms where room 1 is the entrance, but the root is not actually important for the computation.

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CF 104974N - Memory Problems

We are given a permutation of the numbers from $0$ to $N-1$, but the permutation itself is unknown. What is known is that every value belongs to a natural pair: $0$ is paired with $1$, $2$ with $3$, and so on.

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CF 104974O - Gift Battle

We are given a multiset of integers, and two players take turns selecting numbers from it under a strict constraint.

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CF 104974M - Friend Management

We are given a tree of $N$ dinosaurs representing Danny’s friend network. Each node has a value $ai$. There are $K$ possible invitations, and each invitation is identified by an integer $i$. If Danny accepts invitation $i$, we remove every node $j$ such that $i$ divides $aj$.

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CF 104974L - Gifts

We are counting sequences of gift-giving events within a finite timeline of $L$ days. Bob starts on day 1 and may choose any day as his first gift. After that, each next gift must occur within at most $K$ days from the previous one.

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CF 104974K - Chocolate Tree

We are given a rooted tree where each node stores a value representing a chocolate type. The tree structure is fixed, but two kinds of operations are performed over time.

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CF 104974J - Bouquet of Flowers

We are given several test cases. In each test case, there are several flower types, each type having a fixed “beauty coefficient” and exactly 100 identical flowers available. Every individual flower costs 1 dinar, and we can buy at most c flowers in total.

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CF 104974I - Collin-Count

We are given a set of distinct points on a 2D plane. The task is to count how many ways we can choose four different points such that all four lie on the same straight line.

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CF 104974H - Chocolate Messages

We are given a collection of strings, each attached to a distinct index from 1 to N. The task is to determine whether we can choose four different indices such that if we concatenate the first two strings in order, we get exactly the same string as concatenating the other two…

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CF 104974F - Painting a Picture

We are given a rectangular grid where each cell is either empty or contains a shop that sells exactly one paint color. Bob starts at the top-left cell and wants to reach the bottom-right cell, moving only in four directions with unit cost per move.

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CF 104974G - Truecaller

Each test case gives a small phonebook of people, where every person has a unique name and an 8-digit phone number. After that, we receive many queries. Each query does not reveal a full phone number; instead, it reveals only a handful of digits, and their order is irrelevant.

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CF 104974D - Traffic Lights

We are moving along a straight road from position 0 to position X, walking at exactly one meter per second. Along the way there are traffic lights placed at fixed coordinates.

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CF 104974E - Intern Florist

We are simulating a very small file system that supports three operations applied sequentially. Each operation either creates a named file, deletes a named file, or asks how many files currently exist.

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CF 104974B - Arcade Game

We are working with an array of length $n$, initially filled with zeros. Then we receive $q$ operations that either ask for a range sum or apply a structured update. A query of the first type asks for the sum of values in a subarray $[l, r]$.

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CF 104974A - Happy Valentine's Day

We are given a short sequence of integer adjustments applied one after another to a running total. Each value can either increase or decrease the sum depending on whether it is positive or non-positive, but in practice they are simply added as-is.