Codeforces Round #FF (Div. 1)

Solutions for Codeforces Round #FF (Div. 1) (contest 446). 2/5 problems verified against sample I/O. Difficulty range: 1600-3100.

5 items

Codeforces Round #FF (Div. 1)

Type: Div. 1 | Problems: 5 | Verified: 2/5 | Rating range: 1600-3100 | Time: 14m 24s

Problem	Name	Rating	Tags	Solve Time	Verified
A	DZY Loves Sequences	1600	dp, implementation, two-pointers	2m 23s	✓
B	DZY Loves Modification	2000	brute-force, data-structures, greedy	2m 23s	✓
C	DZY Loves Fibonacci Numbers	2400	data-structures, math, number-theory	6m 32s	✗
D	DZY Loves Games	2800	math, matrices, probabilities	1m 41s	✗
E	DZY Loves Bridges	3100	math, matrices	1m 25s	✗

Practice › Codeforces Solutions › Codeforces Round #FF (Div. 1) ›

CF 446A - DZY Loves Sequences

We are given an array of up to $10^5$ integers. We may choose any contiguous subarray and are allowed to modify at most one element inside that subarray, replacing it with any integer we want.

Practice › Codeforces Solutions › Codeforces Round #FF (Div. 1) ›

CF 446B - DZY Loves Modification

We have an n × m matrix of integers. We must perform exactly k operations. An operation chooses either an entire row or an entire column. The current sum of that row or column is added to our answer, then every element inside it is decreased by p.

Practice › Codeforces Solutions › Codeforces Round #FF (Div. 1) ›

CF 446C - DZY Loves Fibonacci Numbers

We are given an array of integers and need to support two types of queries efficiently. The first type requires adding Fibonacci numbers to a contiguous subarray: for indices from l to r, we add F₁ to the element at l, F₂ to the element at l+1, up to F{r-l+1} at position r.

Practice › Codeforces Solutions › Codeforces Round #FF (Div. 1) ›

CF 446D - DZY Loves Games

We are given an undirected connected graph representing a maze of rooms. DZY starts at room 1 with a fixed number of lives. Each time he is in a room, he randomly chooses one of its outgoing corridors uniformly and moves to the adjacent room.

Practice › Codeforces Solutions › Codeforces Round #FF (Div. 1) ›

CF 446E - DZY Loves Bridges

We are dealing with a very large directed walk-counting problem on a graph that is heavily structured but too large to ever build explicitly. There are $2m$ islands, and DZY starts from a home node. From home, he can move to island $i$ in $ai$ different ways.