Good Bye 2019

9 problems from Good Bye 2019 (contest 1270), difficulty 800-3500. 2/9 solutions verified against sample I/O.

9 items

Good Bye 2019

Special | 9 problems | 2/9 verified | Difficulty 800-3500 | 55m 51s

#	Problem	Rating	Tags	Accepted	Time	✓
A	Card Game	800	games, greedy, math	17,812	2m 47s
B	Interesting Subarray	1200	constructive-algorithms, greedy, math	17,372	10m 31s
C	Make Good	1400	bitmasks, constructive-algorithms, math	15,038	5m 12s
D	Strange Device	1900	constructive-algorithms, interactive, math	4,868	2m 34s	✓
E	Divide Points	2300	constructive-algorithms, geometry, math	2,746	4m 59s
F	Awesome Substrings	2600	math, strings	1,336	2m 22s	✓
G	Subset with Zero Sum	2700	constructive-algorithms, dfs-and-similar, graphs	2,956	5m 39s
H	Number of Components	3300	data-structures	1,005	5m 25s
I	Xor on Figures	3500	constructive-algorithms, fft, math	317	16m 22s

Practice › Codeforces Solutions › Good Bye 2019 ›

CF 1270I - Xor on Figures

We are given a toroidal grid of size $2^k times 2^k$, where each cell contains a 60-bit integer. The grid wraps around both horizontally and vertically, so shifting beyond an edge brings us back to the opposite side.

Practice › Codeforces Solutions › Good Bye 2019 ›

CF 1270G - Subset with Zero Sum

We are given an array of integers where each position i has a value a[i] constrained in a tight interval that depends on its index. The i-th element is never too negative and never too large: it always lies between i − n and i − 1.

Practice › Codeforces Solutions › Good Bye 2019 ›

CF 1270H - Number of Components

The array defines a complete ordering between positions: for every pair of indices $i < j$, we draw a directed comparison that becomes an undirected edge if the value on the left is smaller than the value on the right.

Practice › Codeforces Solutions › Good Bye 2019 ›

CF 1270B - Interesting Subarray

We are given several test cases, and each test case provides an array of integers. The task is to determine whether there exists a contiguous segment of this array whose spread is large enough compared to its length.

Practice › Codeforces Solutions › Good Bye 2019 ›

CF 1270F - Awesome Substrings

We are given a binary string and asked to count how many of its contiguous substrings satisfy a very specific structural constraint. A substring is considered valid if it contains at least one 1, and if its total length is divisible by the number of 1s inside it.

Practice › Codeforces Solutions › Good Bye 2019 ›

CF 1270E - Divide Points

We are given a collection of points on a plane, each with integer coordinates, and we must split them into two nonempty groups. After splitting, every pair of points produces a distance value, since we consider Euclidean distances between all pairs.

Practice › Codeforces Solutions › Good Bye 2019 ›

CF 1270C - Make Good

We are given an array of nonnegative integers, and we are allowed to append at most three additional numbers. The goal is to make the final multiset of numbers satisfy a very specific algebraic condition: the sum of all elements must equal twice their bitwise XOR.

Practice › Codeforces Solutions › Good Bye 2019 ›

CF 1270D - Strange Device

We are given an unknown array of distinct integers. We cannot read it directly. Instead, we can query any subset of exactly k positions, and the device returns the position and value of the element that would rank as the m-th smallest among those k values.

Practice › Codeforces Solutions › Good Bye 2019 ›

CF 1270A - Card Game

There is not enough information to diagnose the bug or provide a corrected solution. The sample with expected output appears to belong to a string construction problem, but you have not provided: - the problem statement, - the original Python solution, - or even the name of…