Codeforces Round 899 (Div. 2)

Solutions for Codeforces Round 899 (Div. 2) (contest 1882). 1/6 problems verified against sample I/O. Difficulty range: 800-3100.

6 items

Codeforces Round 899 (Div. 2)

Type: Div. 2 | Problems: 6 | Verified: 1/6 | Rating range: 800-3100 | Time: 11m 50s

Problem Name Rating Tags Solve Time Verified
A Increasing Sequence 800 greedy 42s ✗
B Sets and Union 1300 bitmasks, brute-force, constructive-algorithms 2m 6s ✓
C Card Game 1500 brute-force, greedy 4m 3s ✗
D Tree XOR 1900 bitmasks, dfs-and-similar, dp 47s ✗
E1 Two Permutations (Easy Version) 2400 brute-force, constructive-algorithms, greedy 2m 18s ✗
E2 Two Permutations (Hard Version) 3100 constructive-algorithms 1m 54s ✗
Practice › Codeforces Solutions › Codeforces Round 899 (Div. 2) ›

CF 1882C - Card Game

We have a deck of cards, each containing an integer value. During the game we repeatedly remove cards from the current deck. If we remove a card at an odd position, its value is added to our score.
codeforces competitive-programming brute-force greedy Jun 8, 2026
Practice › Codeforces Solutions › Codeforces Round 899 (Div. 2) ›

CF 1882E2 - Two Permutations (Hard Version)

We are given two independent permutations, one of length $n$ and another of length $m$. We repeatedly apply a synchronized operation: in each step we choose a position in each array, then rotate each array so that the chosen element becomes the last element, preserving…
codeforces competitive-programming constructive-algorithms Jun 8, 2026
Practice › Codeforces Solutions › Codeforces Round 899 (Div. 2) ›

CF 1882E1 - Two Permutations (Easy Version)

We are given two permutations, one of size $n$ and one of size $m$, which are simply arrays containing all integers from 1 to $n$ and 1 to $m$ in some order. The goal is to transform both permutations into their sorted forms simultaneously, using a specific operation.
codeforces competitive-programming brute-force constructive-algorithms greedy number-theory Jun 8, 2026
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CF 1882B - Sets and Union

We are given several sets of integers. We can choose any subset of these sets (including none) and take the union of the selected sets. A set is attainable if it can be formed in this way.
codeforces competitive-programming bitmasks brute-force constructive-algorithms greedy Jun 8, 2026
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CF 1882D - Tree XOR

We have a tree where each vertex contains a number. After choosing a root, we may repeatedly pick a vertex and XOR every value inside its subtree by some non-negative integer c. Applying such a spell costs (subtree size) × c.
codeforces competitive-programming bitmasks dfs-and-similar dp greedy trees Jun 8, 2026
Practice › Codeforces Solutions › Codeforces Round 899 (Div. 2) ›

CF 1882A - Increasing Sequence

We need to construct a new sequence $b$ of length $n$. Every element of $b$ must be a positive integer. The sequence must be strictly increasing, and for every position $i$, we are forbidden from choosing $bi = ai$.
codeforces competitive-programming greedy Jun 8, 2026