ICPC 2019-2020 NERC (NEERC), Southern and Volga Russia Qualifier
11 problems from ICPC 2019-2020 NERC (NEERC), Southern and Volga Russia Qualifier (contest 102348), difficulty -. 8/11 solutions verified against sample I/O.
ICPC 2019-2020 NERC (NEERC), Southern and Volga Russia Qualifier
ICPC/IOI | 11 problems | 8/11 verified | Difficulty - | 1h 21m
| # | Problem | Rating | Tags | Accepted | Time | ✓ |
|---|---|---|---|---|---|---|
| B | Interesting Vertices | 1m 54s | ✓ | |||
| C | Marbles | 22m 18s | ||||
| D | Ticket Game | 3m 11s | ✓ | |||
| E | Painting The Fence | 14m 4s | ✓ | |||
| F | The Number of Products | 14m 40s | ||||
| G | Swap Letters | 3m 44s | ||||
| H | Berland Prospect | 5m 54s | ✓ | |||
| I | Radio Stations | 6m 2s | ✓ | |||
| J | Monocarp and T-Shirts | 3m 42s | ✓ | |||
| K | Moonbound | 2m 38s | ✓ | |||
| L | Printer | 3m 17s | ✓ |
CF 102348H - Berland Prospect
We have n lanterns placed at strictly increasing integer coordinates x[0], x[1], ..., x[n-1]. We may choose any subset of them to leave switched on.
CF 102348F - The Number of Products
We have an array of (n) integers, and every contiguous subarray contributes according to the sign of its product. For each pair of endpoints (l le r), the product of (al,a{l+1},ldots,ar) is either negative, zero, or positive.
CF 102348C - Marbles
We have a row of (n) marbles, where each marble has one of at most 20 colors. We may swap neighboring marbles, and the goal is to make every color occupy one contiguous block. The blocks themselves may appear in any order.
CF 102348G - Swap Letters
We have two strings s and t of the same length. Every position contains either a or b. One operation chooses any position in s and any position in t, then swaps the two characters.
CF 102348E - Painting The Fence
We have a row of (n) fence planks and (m) colors. Color (i) is available for exactly (ai) planks, and the values sum to (n), so every unit of paint must be used.
CF 102348K - Moonbound
We need to construct an (n times n) checkerboard, where cell ((i,j)) must contain stone if (i+j) is even and sand otherwise. The value (n) is even and at most (50). The difficulty is not choosing the final colors. The difficulty is the order in which cells can be reached.
CF 102348L - Printer
We have two rows of n tables, one row for each floor. A 1 at position i means a team occupies that table, while 0 means the table is free. The printer may be installed on any table, including an occupied one. Suppose the printer is at position p on one chosen floor.
CF 102348J - Monocarp and T-Shirts
There are (n) friends, and each friend wants a different T-shirt size. Monocarp enters one contest for every friend and requests exactly that friend's size.
CF 102348I - Radio Stations
We have (p) radio stations. Choosing station (i) means signing a contract with it, and this is possible only when the chosen signal power (f) lies inside its interval ([li,ri]). For a fixed (f), a station outside its interval is forced to remain unselected.
CF 102348D - Ticket Game
We have an even-length ticket split into two equal halves. Every position already contains a digit or contains ?, meaning that its digit has been erased. The two players alternately choose one remaining ? and replace it with any digit from 0 through 9.
CF 102348B - Interesting Vertices
We have a tree whose vertices are numbered from 1 to (n), and exactly (k) of those vertices are colored. For an uncolored vertex (x), imagine cutting (x) away from the tree. Every neighbor of (x) becomes the root of one connected component.