2019-2020 10th BSUIR Open Programming Championship. Semifinal

12 problems from 2019-2020 10th BSUIR Open Programming Championship. Semifinal (contest 103637), difficulty -. 12/12 solutions verified against sample I/O.

12 items

2019-2020 10th BSUIR Open Programming Championship. Semifinal

Special | 12 problems | 12/12 verified | Difficulty - | 11m 13s

# Problem Rating Tags Accepted Time ✓
A Agile permutation 49s ✓
B BSUIR Open X 52s ✓
C Crossed out letter 45s ✓
D Dull game 1m 12s ✓
E Elegance in moves 49s ✓
F Function analysis 49s ✓
G Geometric shapes 50s ✓
H Hockey championship 2m 12s ✓
I Items in boxes 43s ✓
J Jenga 42s ✓
K K-ones xor 48s ✓
L Long integer 42s ✓
Practice › Codeforces Solutions › 2019-2020 10th BSUIR Open Programming Championship. Semifinal ›

CF 103637H - Hockey championship

We are given a patient who may suffer from exactly one disease among $k$ candidates. There are $n$ available medical tests. Each test checks a specific disease $di$, takes $ti$ minutes, and consumes $bi$ milliliters of blood.
codeforces competitive-programming Jul 3, 2026
Practice › Codeforces Solutions › 2019-2020 10th BSUIR Open Programming Championship. Semifinal ›

CF 103637A - Agile permutation

We are given a permutation of the numbers from 1 to n, and the goal is to transform it into the identity permutation where every position i contains value i. Two operations are available. One operation lets us swap any two elements at a fixed cost a.
codeforces competitive-programming Jul 3, 2026
Practice › Codeforces Solutions › 2019-2020 10th BSUIR Open Programming Championship. Semifinal ›

CF 103637L - Long integer

We are maintaining a very large integer that starts as an initial decimal string. The number is then modified step by step by a sequence of operations. Each operation either appends a single digit to the right end of the current number or removes the rightmost digit.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › 2019-2020 10th BSUIR Open Programming Championship. Semifinal ›

CF 103637K - K-ones xor

We are given an array of $n$ integers, each represented with at most $m$ bits. We are allowed to choose a mask $x$, also an $m$-bit number, but with the restriction that it contains at most $k$ set bits.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › 2019-2020 10th BSUIR Open Programming Championship. Semifinal ›

CF 103637J - Jenga

We are asked to count how many valid Jenga towers can be formed using exactly $n$ identical blocks, under a specific notion of stability. A tower is built in horizontal layers. Each layer contains one or more blocks, and adjacent layers are oriented perpendicular to each other.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › 2019-2020 10th BSUIR Open Programming Championship. Semifinal ›

CF 103637I - Items in boxes

We are given two integers. One of them, $n$, determines how many boxes exist, specifically $2n$ boxes in total. The second value, $a$, describes how many distinct items are inside each box, and every box is independent of the others. From each box we must pick exactly one item.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › 2019-2020 10th BSUIR Open Programming Championship. Semifinal ›

CF 103637G - Geometric shapes

We are given a rectangular grid of size $n times m$. One cell $(r, c)$ is forbidden and must remain empty. All other cells must be covered completely using tetrominoes, where each tetromino occupies exactly four cells and can be any of the standard Tetris shapes under rotation…
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › 2019-2020 10th BSUIR Open Programming Championship. Semifinal ›

CF 103637F - Function analysis

We are given a permutation-like sequence $p = (1, 2, dots, n)$. From this sequence we repeatedly sample $m$ elements, where each position is chosen independently and uniformly from the $n$ positions, so repetitions are allowed and the resulting multiset is not necessarily…
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › 2019-2020 10th BSUIR Open Programming Championship. Semifinal ›

CF 103637D - Dull game

We are given a sequence of heap sizes, and we are allowed to repeatedly modify individual heap values. After each modification, we must select a subsequence of indices that satisfies a very specific game-theoretic condition.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › 2019-2020 10th BSUIR Open Programming Championship. Semifinal ›

CF 103637E - Elegance in moves

We are working on a very large chessboard where most cells are usable, but some disjoint rectangular regions are forbidden. The rectangles do not overlap, and each cell belongs to at most one of them.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › 2019-2020 10th BSUIR Open Programming Championship. Semifinal ›

CF 103637B - BSUIR Open X

We are given a collection of strings, each representing the code name of a task set. From this collection we must choose exactly two distinct strings, and we are allowed to place them in either order, concatenating one after the other.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › 2019-2020 10th BSUIR Open Programming Championship. Semifinal ›

CF 103637C - Crossed out letter

We are given two strings, both of the same length. Each of them is known to come from some unknown original string by deleting exactly one character, but not necessarily the same position in both cases.
codeforces competitive-programming Jul 2, 2026