Contest 2050 and Codeforces Round 718 (Div. 1 + Div. 2)

Solutions for Contest 2050 and Codeforces Round 718 (Div. 1 + Div. 2) (contest 1517). 4/8 problems verified against sample I/O. Difficulty range: 800-3500.

8 items

Contest 2050 and Codeforces Round 718 (Div. 1 + Div. 2)

Type: Div. 1+2 | Problems: 8 | Verified: 4/8 | Rating range: 800-3500 | Time: 18m 5s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Sum of 2050	800	greedy, math	2m 6s	✓
B	Morning Jogging	1200	constructive-algorithms, greedy, sortings	2m 55s	✗
C	Fillomino 2	1400	constructive-algorithms, dfs-and-similar, greedy	2m 17s	✓
D	Explorer Space	1800	dp, graphs, shortest-paths	1m 7s	✓
E	Group Photo	2500	binary-search, data-structures, implementation	2m 22s	✗
F	Reunion	3200	combinatorics, dp, trees	2m 47s	✗
G	Starry Night Camping	3300	constructive-algorithms, flows, graphs	2m 10s	✓
H	Fly Around the World	3500	dp, geometry	2m 21s	✗

Practice › Codeforces Solutions › Contest 2050 and Codeforces Round 718 (Div. 1 + Div. 2) ›

CF 1517H - Fly Around the World

We are given a sequence of real values $b1, b2, ldots, bn$, which can be interpreted as the altitude of an aircraft at $n$ checkpoints. Each checkpoint restricts the allowed altitude range, so every $bi$ must lie inside a fixed interval.

Practice › Codeforces Solutions › Contest 2050 and Codeforces Round 718 (Div. 1 + Div. 2) ›

CF 1517F - Reunion

Method 1b already provides the key idea. If $(umldots u1u0)3$ is a ternary integer, its decimal value is obtained from the nested form $$(cdots((umcdot3+u{m-1})cdot3+u{m-2})cdots)cdot3+u0.$$ For pencil-and-paper work this means: Start with the leading digit.

Practice › Codeforces Solutions › Contest 2050 and Codeforces Round 718 (Div. 1 + Div. 2) ›

CF 1517G - Starry Night Camping

Each tent is placed at an integer coordinate and has a positive weight. We may remove any subset of tents. The goal is to maximize the total weight of the tents that remain. The restriction only applies to important tents, meaning tents whose coordinates are both even.

Practice › Codeforces Solutions › Contest 2050 and Codeforces Round 718 (Div. 1 + Div. 2) ›

CF 1517E - Group Photo

We are given a line of n people, each holding a card labeled either 'C' or 'P'. Each arrangement of cards forms a candidate photo.

Practice › Codeforces Solutions › Contest 2050 and Codeforces Round 718 (Div. 1 + Div. 2) ›

CF 1517D - Explorer Space

We are given a two-dimensional grid representing the explorer space at a conference. Each cell in the grid is a vertex, and each adjacent pair of vertices (up, down, left, right) is connected by an edge with a weight representing the number of exhibits along that edge.

Practice › Codeforces Solutions › Contest 2050 and Codeforces Round 718 (Div. 1 + Div. 2) ›

CF 1517B - Morning Jogging

Practice › Codeforces Solutions › Contest 2050 and Codeforces Round 718 (Div. 1 + Div. 2) ›

CF 1517C - Fillomino 2

We are given an $n times n$ lower-triangular part of a chessboard, where only the diagonal and the cells below it matter. On the main diagonal, each cell contains a distinct integer from 1 to $n$, forming a permutation.

Practice › Codeforces Solutions › Contest 2050 and Codeforces Round 718 (Div. 1 + Div. 2) ›

CF 1517A - Sum of 2050

We are asked to take a number $n$ and express it as a sum of numbers that are multiples of 2050 scaled by powers of ten. Concretely, the numbers we can use are 2050, 20500, 205000, 2050000, and so on. Each number in this sequence is exactly 2050 multiplied by a power of ten.