Codeforces Round 686 (Div. 3)

Solutions for Codeforces Round 686 (Div. 3) (contest 1454). 2/6 problems verified against sample I/O. Difficulty range: 800-2100.

6 items

Codeforces Round 686 (Div. 3)

Type: Div. 3 | Problems: 6 | Verified: 2/6 | Rating range: 800-2100 | Time: 24m 40s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Special Permutation	800	constructive-algorithms, probabilities	7m 42s	✗
B	Unique Bid Auction	800	implementation	1m 23s	✓
C	Sequence Transformation	1200	greedy, implementation	10m 13s	✓
D	Number into Sequence	1300	constructive-algorithms, math, number-theory	1m 44s	✗
E	Number of Simple Paths	2000	combinatorics, dfs-and-similar, graphs	1m 47s	✗
F	Array Partition	2100	binary-search, data-structures, greedy	1m 51s	✗

Practice › Codeforces Solutions › Codeforces Round 686 (Div. 3) ›

CF 1454C - Sequence Transformation

We are given a sequence of integers, and the goal is to make all elements equal by repeatedly removing contiguous segments that do not contain a chosen value $x$. The choice of $x$ is critical because once we pick it, it cannot change.

Practice › Codeforces Solutions › Codeforces Round 686 (Div. 3) ›

CF 1454A - Special Permutation

The task is to construct a permutation of length (n 1) such that no element occupies its original position. In other words, for a permutation (p) of size (n), we require that (pi ne i) for every index (i).

Practice › Codeforces Solutions › Codeforces Round 686 (Div. 3) ›

CF 1454F - Array Partition

We are given an array and we want to cut it into three consecutive non-empty segments. Let us call them the left part, the middle part, and the right part.

Practice › Codeforces Solutions › Codeforces Round 686 (Div. 3) ›

CF 1454E - Number of Simple Paths

We are given a connected undirected graph where the number of edges equals the number of vertices. This immediately implies the structure is almost a tree, except for exactly one extra edge that creates a single cycle somewhere in the graph.

Practice › Codeforces Solutions › Codeforces Round 686 (Div. 3) ›

CF 1454D - Number into Sequence

We are given a single integer $n$, and we want to break it into a sequence of integers greater than 1. These integers are not arbitrary factors, but are constrained by a divisibility chain: each next number must be divisible by the previous one.

Practice › Codeforces Solutions › Codeforces Round 686 (Div. 3) ›

CF 1454B - Unique Bid Auction

We are asked to determine the winner of a simplified "Unique Bid Auction." Each participant chooses a number, and the winner is the participant who picked a number that no one else picked, and that is the smallest among all such unique numbers.