2023-2024 ICPC, Asia Jakarta Regional Contest (Online Mirror, Unrated, ICPC Rules, Teams Preferred)
Solutions for 2023-2024 ICPC, Asia Jakarta Regional Contest (Online Mirror, Unrated, ICPC Rules, Teams Preferred) (contest 1906). 10/13 problems verified against sample I/O. Difficulty range: 1000-3000.
2023-2024 ICPC, Asia Jakarta Regional Contest (Online Mirror, Unrated, ICPC Rules, Teams Preferred)
Type: ICPC/IOI | Problems: 13 | Verified: 10/13 | Rating range: 1000-3000 | Time: 25m 58s
| Problem | Name | Rating | Tags | Solve Time | Verified |
|---|---|---|---|---|---|
| A | Easy As ABC | 1000 | brute-force | 1m 20s | ✓ |
| B | Button Pressing | 2600 | bitmasks, constructive-algorithms, hashing | 1m 46s | ✗ |
| C | Cursed Game | 3000 | interactive | 1m 18s | ✓ |
| D | Spaceship Exploration | 2800 | binary-search, geometry | 4m 37s | ✗ |
| E | Merge Not Sort | 1900 | constructive-algorithms, dp | 2m 35s | ✗ |
| F | Maximize The Value | 2100 | data-structures, sortings | 1m 45s | ✓ |
| G | Grid Game 2 | 2900 | games, number-theory | 2m 21s | ✓ |
| H | Twin Friends | 2200 | combinatorics, dp | 1m 11s | ✓ |
| I | Contingency Plan 2 | 2900 | graph-matchings | 1m 39s | ✓ |
| J | Count BFS Graph | 2100 | combinatorics, dp | 1m 18s | ✓ |
| K | Deck-Building Game | 2500 | divide-and-conquer, math | 3m 22s | ✓ |
| L | Palindromic Parentheses | 2500 | constructive-algorithms | 1m 31s | ✓ |
| M | Triangle Construction | 1700 | greedy, math | 1m 15s | ✓ |
CF 1906K - Deck-Building Game
Each card can end up in one of three states. A card may be placed in your deck, placed in your friend's deck, or discarded entirely. Let the XOR of your deck be X and the XOR of your friend's deck be Y.
CF 1906D - Spaceship Exploration
We are working in a geometric setting where a large convex polygon represents a forbidden region. A spaceship starts outside this region and must travel to another point, with the constraint that it is never allowed to enter the interior of the polygon, though touching its…
CF 1906I - Contingency Plan 2
The network is a tree, so initially there is exactly one simple path between every pair of computers. Each edge, when put into emergency mode, becomes a directed constraint: one endpoint must come before the other in a global ordering of all nodes.
CF 1906H - Twin Friends
We are given two strings, $A$ of length $N$ and $B$ of length $M$ with $N le M$, representing the names of two twins. We want to create nicknames $A'$ and $B'$ for them.
CF 1906E - Merge Not Sort
We are asked to reverse-engineer the merge step of a Merge Sort-like routine, but with a twist: the two input arrays may not be sorted. Concretely, we receive a single array C of length 2N containing every integer from 1 to 2N exactly once.
CF 1906B - Button Pressing
We have a line of lamps, each either on or off, and a line of buttons, one per lamp. Each button affects only the lamps immediately adjacent to it: pressing button $i$ toggles lamps $i-1$ and $i+1$, if they exist.
CF 1906M - Triangle Construction
We are given a convex regular polygon with $N$ sides. Each side $i$ contains $Ai$ special points placed uniformly along the boundary segment of that side.
CF 1906L - Palindromic Parentheses
We are asked to construct a sequence of parentheses of even length $N$ such that it is balanced, meaning every opening parenthesis has a corresponding closing parenthesis and the nesting is correct.
CF 1906J - Count BFS Graph
We are given a fixed ordering of all vertices, starting from node 1, and this ordering is claimed to be the order in which a BFS discovers nodes in some undirected simple graph.
CF 1906G - Grid Game 2
We are asked to analyze a two-player game played on an enormous grid of size $10^9 times 10^9$. Each cell can be either black or white. Initially, only $N$ specific cells are black, and all others are white. Players take turns choosing a black cell.
CF 1906F - Maximize The Value
We are given an array of size $N$, initially filled with zeros. There are $M$ operations; each operation is described by three integers $Li, Ri, Xi$, meaning that if we execute this operation, we add $Xi$ to every element in positions $Li$ through $Ri$.
CF 1906C - Cursed Game
We are asked to play an interactive game against a demon, who hides a 3×3 secret grid with at least one hole. For each round, we are given an odd integer $N$ and must submit an $N times N$ grid of black and white cells.
CF 1906A - Easy As ABC
We are given a fixed 3 by 3 grid of characters, each cell containing one of three letters: A, B, or C. From this grid we want to construct a word of length exactly three by selecting three distinct cells in sequence.