2020-2021 ICPC Southwestern European Regional Contest (SWERC 2020)
13 problems from 2020-2021 ICPC Southwestern European Regional Contest (SWERC 2020) (contest 103081), difficulty -. 12/13 solutions verified against sample I/O.
2020-2021 ICPC Southwestern European Regional Contest (SWERC 2020)
ICPC/IOI | 13 problems | 12/13 verified | Difficulty - | 13m 11s
| # | Problem | Rating | Tags | Accepted | Time | ✓ |
|---|---|---|---|---|---|---|
| A | Gratitude | 49s | ✓ | |||
| B | Rule 110 | 56s | ✓ | |||
| C | Safe Distance | 51s | ✓ | |||
| D | Jogging | 1m 1s | ✓ | |||
| E | Cakes | 40s | ✓ | |||
| F | Mentors | 55s | ✓ | |||
| G | Decoration | 53s | ✓ | |||
| H | Figurines | 54s | ✓ | |||
| I | Emails | 57s | ✓ | |||
| J | Daisy's Mazes | 52s | ✓ | |||
| K | Unique Activities | 50s | ✓ | |||
| L | Restaurants | 2m 31s | ||||
| M | Fantasmagorie | 1m 2s | ✓ |
CF 103081D - Jogging
We are given an undirected weighted graph where vertices are intersections and edges are streets with lengths. Phoebe always starts and ends every jogging session at node 0.
CF 103081I - Emails
We are given a set of people represented as nodes in an undirected graph. An edge between two nodes means those two people initially know each other’s email addresses. The system evolves in synchronous rounds.
CF 103081K - Unique Activities
We are given a single long string made of uppercase English letters. Think of it as a timeline of activities. Each character is one activity, and any contiguous segment of this timeline is considered a “subsequence of days” we can inspect.
CF 103081L - Restaurants
The function $tau(x)$ in Section 7.2.1.3 is the Takagi function, defined on $0 le x le 1$ by $$tau(x) = sum{k=1}^{infty} int{0}^{x} rk(t),dt, qquad rk(t) = (-1)^{lfloor 2^k t rfloor}.$$ For each real $r$, define the level set $$L(r) = {x in [0,1] : tau(x) = r}.
CF 103081M - Fantasmagorie
We are given two black and white grids of size $W times H$. Each grid is not arbitrary: it obeys strong structural constraints that heavily restrict how the black and white cells can be arranged.
CF 103081J - Daisy's Mazes
We are given a directed graph of rooms. Each edge represents a one-way door and carries a color label. Daisy starts in room 0 and wants to reach room R − 1. Her movement depends on a stack of colored cards. At any moment she is in a room with a current stack.
CF 103081H - Figurines
We are given a system with $N$ figurines labeled from $0$ to $N-1$. Over $N$ days, each figurine is inserted onto a shelf exactly once and later removed exactly once, so every figurine defines a continuous active interval $[lj, rj)$.
CF 103081G - Decoration
We are asked to construct a sequence of integers representing vertical gaps between consecutive shelves. There are $K$ gaps, each gap $si$ must be an integer in the range $[0, N-1]$, and all gaps must be pairwise distinct.
CF 103081F - Mentors
We are counting hierarchical structures built over $N$ labeled people, where labels encode a strict seniority order.
CF 103081E - Cakes
We are given a recipe that consists of several ingredients, and for each ingredient we know two numbers: how much of it is needed to bake one cake and how much of it is currently available in the kitchen.
CF 103081B - Rule 110
We are given an infinite one dimensional line of cells, each cell holding either zero or one. Initially, only a block of 16 cells is explicitly specified; everything outside this block is zero.
CF 103081C - Safe Distance
We are given a rectangular room in the plane, anchored at the origin and extending to the point $(X, Y)$. Inside this rectangle there are several fixed points representing other people.
CF 103081A - Gratitude
We are given a chronological log of Ben’s daily gratitude notes. Each day contributes exactly three independent text entries, and across all days we therefore have a sequence of 3N strings in total. Each string represents one “thing” Ben wrote down.