2026 ICPC Asia Pacific Championship - Online Mirror (Unrated, Online Mirror, ICPC Rules, Teams Preferred)
13 problems from 2026 ICPC Asia Pacific Championship - Online Mirror (Unrated, Online Mirror, ICPC Rules, Teams Preferred) (contest 2206), difficulty 1300-3500. 3/13 solutions verified against sample I/O.
2026 ICPC Asia Pacific Championship - Online Mirror (Unrated, Online Mirror, ICPC Rules, Teams Preferred)
ICPC/IOI | 13 problems | 3/13 verified | Difficulty 1300-3500 | 28m 52s
| # | Problem | Rating | Tags | Accepted | Time | ✓ |
|---|---|---|---|---|---|---|
| A | Compare Suffixes | 3500 | interactive | 84 | 1m 54s | |
| B | Subtree Removal Game | 2500 | binary-search, games, trees | 347 | 2m 20s | ✓ |
| C | Upside Down Dijkstra | 2200 | dfs-and-similar | 625 | 2m 25s | |
| D | Christmas Tree Un-decoration | 2600 | data-structures, dp, trees | 240 | 2m 3s | ✓ |
| E | Parallel Sums | 2500 | data-structures, geometry | 404 | 4m 45s | |
| F | Minesweeper String | 2400 | fft, number-theory | 422 | 50s | |
| G | Extra Transition | 3100 | graphs | 77 | 2m 15s | |
| H | Reflect Sort | 1800 | number-theory | 846 | 1m 42s | |
| I | Growth Factor | 2900 | combinatorics, dp, math | 166 | 1m 10s | ✓ |
| J | Worldwide Playlist | 1700 | math | 999 | 2m 16s | |
| K | Time Display Stickers | 1300 | binary-search | 1,403 | 2m 34s | |
| L | Onion | 3500 | 39 | 2m 52s | ||
| M | Deformed Balance | 2900 | 47 | 1m 46s |
CF 2206L - Onion
We are given a large set of points on a two-dimensional plane, constructed using a simple linear function modulo $n$. Specifically, each point has coordinates $(x, y)$ where $x$ ranges from $0$ to $n-1$, and $y = (a cdot x + b) bmod n$.
CF 2206M - Deformed Balance
We are given a parenthesis string $S$, and we are allowed to add some parentheses in front of it and some at the end.
CF 2206K - Time Display Stickers
We are given a collection of digit stickers as a string. Each character represents one sticker of that digit. The goal is to assemble as many valid time displays in the format HH:MM, where HH is a two-digit hour between 00 and 11 inclusive, and MM is a two-digit minute between…
CF 2206J - Worldwide Playlist
We are given a music playlist of n unique songs arranged in some initial order a. The app plays the songs in a circular fashion: after the last song, it starts over from the first. Separately, we have a desired listening sequence b of the same n songs.
CF 2206E - Parallel Sums
We are given a sequence of n integers A = [a1, a2, ..., an], but we do not know A itself. Instead, we are provided with a sequence of parallel sums of length n - m + 1, where each sum is the sum of m consecutive elements of A. Formally, the sums are si = ai + a{i+1} + ...
CF 2206I - Growth Factor
We are counting how many ways we can build a sequence of integers when each position has an upper limit, and each element must divide the next one. More concretely, at position i we choose a value bi that cannot exceed ai.
CF 2206H - Reflect Sort
We are given an integer array and a somewhat unusual operation that allows us to “reflect” values around a chosen pivot element.
CF 2206G - Extra Transition
We are given a connected undirected graph on $n$ vertices, where vertex $1$ is a start and vertex $n$ is a finish.
CF 2206D - Christmas Tree Un-decoration
We are given a rooted tree where vertex 1 is the root, and every node carries a pile of ornaments. The only way we are allowed to remove ornaments is by selecting a vertex $u$, and then subtracting one ornament from every node on the path from the root to $u$, as long as that…
CF 2206F - Minesweeper String
We are given a string of digits, each representing a cell in a conceptual 1D array of length $n$. Each digit either corresponds to some mines if it is non-zero, or an empty cell if it is zero.
CF 2206C - Upside Down Dijkstra
We are given a connected undirected graph with $n$ vertices and $m$ edges, where each edge connects two vertices but its weight is unknown.
CF 2206B - Subtree Removal Game
We are given a rooted tree with nodes numbered from 1 to $n$, rooted at node 1. Each node may either have an integer written on it (leaves) or be empty (internal nodes).
CF 2206A - Compare Suffixes
We are tasked with sorting the suffixes of a hidden string $S$ using an interactive judge. The string has length $n$, and we do not know its contents. We can query any two suffixes $S(i)$ and $S(j)$ to learn which is lexicographically smaller.