Codeforces Round 922 (Div. 2)

Solutions for Codeforces Round 922 (Div. 2) (contest 1918). 2/7 problems verified against sample I/O. Difficulty range: 800-2700.

7 items

Codeforces Round 922 (Div. 2)

Type: Div. 2 | Problems: 7 | Verified: 2/7 | Rating range: 800-2700 | Time: 15m 17s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Brick Wall	800	constructive-algorithms, greedy, implementation	1m 30s	✓
B	Minimize Inversions	900	constructive-algorithms, data-structures, greedy	2m 52s	✗
C	XOR-distance	1400	bitmasks, greedy, implementation	2m 54s	✗
D	Blocking Elements	1900	binary-search, data-structures, dp	2m 7s	✗
E	ace5 and Task Order	2200	constructive-algorithms, divide-and-conquer, implementation	2m 19s	✗
F	Caterpillar on a Tree	2500	dfs-and-similar, graphs, greedy	2m 11s	✗
G	Permutation of Given	2700	constructive-algorithms, math	1m 24s	✓

Practice › Codeforces Solutions › Codeforces Round 922 (Div. 2) ›

CF 1918E - ace5 and Task Order

We are given a hidden permutation of integers from 1 to $n$. The permutation is unknown, and our goal is to determine it.

Practice › Codeforces Solutions › Codeforces Round 922 (Div. 2) ›

CF 1918F - Caterpillar on a Tree

The previous attempts failed for two reasons. First, the test harness was calling a solvecase function that either wasn’t defined in the scope, producing a NameError.

Practice › Codeforces Solutions › Codeforces Round 922 (Div. 2) ›

CF 1918G - Permutation of Given

We are asked to construct an array of length $n$ containing non-zero integers such that if we replace each element by the sum of its neighbors, the resulting array is a permutation of the original array. For the endpoints, the "neighbor sum" is just the single adjacent element.

Practice › Codeforces Solutions › Codeforces Round 922 (Div. 2) ›

CF 1918D - Blocking Elements

We are given an array of positive integers. Our goal is to "block" some elements in order to minimize a certain cost.

Practice › Codeforces Solutions › Codeforces Round 922 (Div. 2) ›

CF 1918C - XOR-distance

The problem asks us to minimize the absolute difference between two numbers after each has been XOR-ed with a single number $x$ that we are allowed to choose.

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CF 1918B - Minimize Inversions

We are given two permutations a and b of the same length. The allowed operation is unusual: whenever we swap positions i and j, we must perform the same swap in both arrays simultaneously. This means we can never separate a[k] from b[k].

Practice › Codeforces Solutions › Codeforces Round 922 (Div. 2) ›

CF 1918A - Brick Wall

We are building a full $n times m$ rectangular grid using long thin bricks, where each brick is a $1 times k$ strip with $k ge 2$. Each brick must lie entirely either horizontally or vertically, and every cell of the grid must belong to exactly one brick.