Codeforces Round 1025 (Div. 2)

8 problems from Codeforces Round 1025 (Div. 2) (contest 2109), difficulty 800-3000. 2/8 solutions verified against sample I/O.

8 items

Codeforces Round 1025 (Div. 2)

Div. 2 | 8 problems | 2/8 verified | Difficulty 800-3000 | 13m 18s

#	Problem	Rating	Tags	Accepted	Time	✓
A	It's Time To Duel	800	implementation	26,948	1m 33s	✓
B	Slice to Survive	1200	bitmasks, greedy, math	17,332	1m 37s	✓
C1	Hacking Numbers (Easy Version)	1500	bitmasks, constructive-algorithms, interactive	11,416	1m 39s
C2	Hacking Numbers (Medium Version)	1700	constructive-algorithms, interactive, math	8,636	1m 50s
C3	Hacking Numbers (Hard Version)	2600	constructive-algorithms, interactive, math	3,202	1m 33s
D	D/D/D	1900	dfs-and-similar, graphs, greedy	5,616	1m 32s
E	Binary String Wowee	2400	combinatorics, dp, strings	1,792	1m 29s
F	Penguin Steps	3000	binary-search, dfs-and-similar, flows	274	2m 5s

Practice › Codeforces Solutions › Codeforces Round 1025 (Div. 2) ›

CF 2109F - Penguin Steps

We are working on an $n times n$ grid where each cell has two attributes: a weight $a{i,j}$ and a color that is either black or white. Two players start from different positions on the left side of the grid and both aim to reach the same exit cell on the rightmost column.

Practice › Codeforces Solutions › Codeforces Round 1025 (Div. 2) ›

CF 2109E - Binary String Wowee

We are given a binary string s of length n and an integer k. Our task is to perform exactly k operations, each of which selects a zero in the current string and flips all bits from the beginning up to that zero.

Practice › Codeforces Solutions › Codeforces Round 1025 (Div. 2) ›

CF 2109C2 - Hacking Numbers (Medium Version)

In this problem, we are asked to manipulate an unknown integer $x$ to become equal to a given target $n$ using a very limited number of operations.

Practice › Codeforces Solutions › Codeforces Round 1025 (Div. 2) ›

CF 2109C3 - Hacking Numbers (Hard Version)

We start with an unknown integer x, hidden from us, guaranteed to lie in the range from 1 to 10^9. Our goal is to transform this hidden value into a given target value n.

Practice › Codeforces Solutions › Codeforces Round 1025 (Div. 2) ›

CF 2109D - D/D/D

We are given a connected, undirected graph with n vertices and m edges. There are no self-loops or multiple edges, so each edge connects two distinct vertices exactly once. Along with the graph, we are given a multiset A of positive integers, each representing a "move length.

Practice › Codeforces Solutions › Codeforces Round 1025 (Div. 2) ›

CF 2109C1 - Hacking Numbers (Easy Version)

In this problem, we face an unknown integer x that is initially hidden from us, and our goal is to transform it into a target integer n by issuing at most seven interactive commands.

Practice › Codeforces Solutions › Codeforces Round 1025 (Div. 2) ›

CF 2109B - Slice to Survive

We are given a rectangular grid of size $n times m$, and a single token (a monster) initially placed at cell $(a, b)$.

Practice › Codeforces Solutions › Codeforces Round 1025 (Div. 2) ›

CF 2109A - It's Time To Duel

We are given a line of players, each participating in duels with their immediate neighbor, so player 1 duels player 2, player 2 duels player 3, and so on until player $n-1$ duels player $n$. After all $n-1$ duels, each player reports whether they won at least one duel.