2026 GBA International Programming Contest

12 problems from 2026 GBA International Programming Contest (contest 106484), difficulty -. 12/12 solutions verified against sample I/O.

12 items

2026 GBA International Programming Contest

Special | 12 problems | 12/12 verified | Difficulty - | 11m 27s

#	Problem	Time	✓
A	Bugcaaaaaat	49s	✓
B	Bugcat's Counting Game	52s	✓
C	Bugcat's Unique Queue	47s	✓
D	Locks	1m	✓
E	Bugcat's Gathering	56s	✓
F	Card Game	47s	✓
G	Skynet	1m 25s	✓
H	Teaching Building	44s	✓
I	Bugcat's Adventure	1m	✓
J	Bugcat's Mahjong	1m 12s	✓
K	Moonlit Trees	53s	✓
L	Pairing Bugcats	1m 2s	✓

Practice › Codeforces Solutions › 2026 GBA International Programming Contest ›

CF 106484H - Teaching Building

We are given a rooted tree with vertices labeled from 1 to 2n, rooted at 1. Each vertex represents a “teaching area” that must appear as a connected region inside a grid of size (n+1) by (2n). Each cell of the grid either contains 0 or one of the labels 1 through 2n.

Practice › Codeforces Solutions › 2026 GBA International Programming Contest ›

CF 106484K - Moonlit Trees

We are given a rooted tree on vertices labeled from 1 to $x$, where vertex 1 is the root and every other vertex $i$ has exactly one parent with a smaller label. So the labels already impose a valid parent structure, but the actual structure of the tree is otherwise free.

Practice › Codeforces Solutions › 2026 GBA International Programming Contest ›

CF 106484G - Skynet

We have a layered defense grid. The drone starts somewhere on the bottom row and moves upward one row at a time. From (r, c) it may go to (r - 1, c - 1), (r - 1, c), or (r - 1, c + 1) as long as the destination is inside the board and not blocked.

Practice › Codeforces Solutions › 2026 GBA International Programming Contest ›

CF 106484D - Locks

We are given an array of positions from 1 to n. Each position behaves like a lock that can be either free or already locked by some query. Initially every position is free.

Practice › Codeforces Solutions › 2026 GBA International Programming Contest ›

CF 106484A - Bugcaaaaaat

We are given a fixed set of seven emoji entries from a chat system used by bugcat creatures. Each entry has a unique identifier from 1 to 7, and each entry can be referred to in exactly two ways.

Practice › Codeforces Solutions › 2026 GBA International Programming Contest ›

CF 106484L - Pairing Bugcats

We are given all binary strings of length $n$, which we can think of as integers from $0$ to $2^n - 1$. These $2^n$ values must be partitioned into $2^{n-1}$ disjoint pairs, so every number is used exactly once.

Practice › Codeforces Solutions › 2026 GBA International Programming Contest ›

CF 106484J - Bugcat's Mahjong

We are given a deck consisting of $n$ colors, and each color appears exactly four times. The full deck therefore has $4n$ cards, and all individual cards are distinct positions in a random permutation of this multiset.

Practice › Codeforces Solutions › 2026 GBA International Programming Contest ›

CF 106484I - Bugcat's Adventure

We are given an undirected graph where each vertex represents a location containing a main monster. Each monster has a fixed strength. Initially there are no helpers. Over time, a vertex may receive at most one helper monster, also with a given strength.

Practice › Codeforces Solutions › 2026 GBA International Programming Contest ›

CF 106484E - Bugcat's Gathering

We are given a directed weighted graph where two travelers start from opposite ends: one begins at node 1 and the other begins at node n. Each edge has a stamina cost if walked normally.

Practice › Codeforces Solutions › 2026 GBA International Programming Contest ›

CF 106484F - Card Game

We are given a stack of uppercase letters arranged from top to bottom. The task is to rebuild these cards into a new sequence by repeatedly removing either the current top card or the current bottom card, and appending that chosen card to the end of a new sequence.

Practice › Codeforces Solutions › 2026 GBA International Programming Contest ›

CF 106484B - Bugcat's Counting Game

We are given a digit-like parameter k between 1 and 9, and a position x. Imagine counting upward from 1, but we do not consider every integer as valid.

Practice › Codeforces Solutions › 2026 GBA International Programming Contest ›

CF 106484C - Bugcat's Unique Queue

We maintain a queue that behaves like a normal FIFO structure, but with one extra rule: every value can appear at most once at any time. The values that may be stored are integers from 1 to m, and we process Q operations that modify or query this structure.