Codeforces Round 928 (Div. 4)

Solutions for Codeforces Round 928 (Div. 4) (contest 1926). 5/7 problems verified against sample I/O. Difficulty range: 800-2200.

7 items

Codeforces Round 928 (Div. 4)

Type: Div. 4 | Problems: 7 | Verified: 5/7 | Rating range: 800-2200 | Time: 13m 14s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Vlad and the Best of Five	800	implementation	1m 29s	✓
B	Vlad and Shapes	800	geometry, implementation	1m 22s	✓
C	Vlad and a Sum of Sum of Digits	1200	dp, implementation	1m 59s	✓
D	Vlad and Division	1300	bitmasks, greedy	2m 3s	✗
E	Vlad and an Odd Ordering	1500	binary-search, bitmasks, data-structures	1m 28s	✓
F	Vlad and Avoiding X	2200	bitmasks, brute-force, dfs-and-similar	3m 16s	✗
G	Vlad and Trouble at MIT	1900	dfs-and-similar, dp, flows	1m 37s	✓

Practice › Codeforces Solutions › Codeforces Round 928 (Div. 4) ›

CF 1926F - Vlad and Avoiding X

We have a fixed $7 times 7$ board whose cells are either black or white. A configuration is considered bad if there exists a black cell whose four diagonal neighbors are also black. Such a pattern looks like an X centered at that cell.

Practice › Codeforces Solutions › Codeforces Round 928 (Div. 4) ›

CF 1926G - Vlad and Trouble at MIT

We are asked to separate music from sleeping students in a dormitory modeled as a tree. Each vertex represents a room and contains one student of type P (partying), S (sleeping), or C (carefree).

Practice › Codeforces Solutions › Codeforces Round 928 (Div. 4) ›

CF 1926D - Vlad and Division

We are given a set of non-negative integers and asked to partition them into groups so that within each group, no two numbers share a 1-bit in the same position across the first 31 bits.

Practice › Codeforces Solutions › Codeforces Round 928 (Div. 4) ›

CF 1926E - Vlad and an Odd Ordering

Vladislav has a deck of cards numbered from 1 to n. He wants to arrange them in a sequence with a peculiar rule. First, he takes all odd numbers and lays them out in increasing order. Then he takes all numbers that are twice an odd number and lays them out in increasing order.

Practice › Codeforces Solutions › Codeforces Round 928 (Div. 4) ›

CF 1926C - Vlad and a Sum of Sum of Digits

For every test case, we are given a number n. Vlad writes all integers from 1 through n on the board. Then each integer is replaced by the sum of its decimal digits. The task is to compute $$sum{i=1}^{n} text{digitSum}(i)$$ where digitSum(i) is the sum of the digits of i.

Practice › Codeforces Solutions › Codeforces Round 928 (Div. 4) ›

CF 1926A - Vlad and the Best of Five

The task is simple: for each string of length five consisting only of the letters A and B, determine which letter occurs more frequently. Each test case provides one such string, and we have multiple test cases to process.

Practice › Codeforces Solutions › Codeforces Round 928 (Div. 4) ›

CF 1926B - Vlad and Shapes

We are given a very small binary image, typically at most 10 by 10 cells. Every cell is either empty or filled. The grid contains exactly one connected geometric figure formed by ones, and that figure is guaranteed to be either a perfect square or a centered triangle (upright…