Codeforces Round 905 (Div. 3)

Solutions for Codeforces Round 905 (Div. 3) (contest 1883). 5/8 problems verified against sample I/O. Difficulty range: 800-1900.

8 items

Codeforces Round 905 (Div. 3)

Type: Div. 3 | Problems: 8 | Verified: 5/8 | Rating range: 800-1900 | Time: 20m 2s

Problem Name Rating Tags Solve Time Verified
A Morning 800 math 1m 46s ✓
B Chemistry 900 strings 1m 46s ✓
C Raspberries 1000 dp, math 6m ✓
D In Love 1500 data-structures, greedy 2m 15s ✓
E Look Back 1700 bitmasks, greedy 1m 52s ✗
F You Are So Beautiful 1400 data-structures 2m 12s ✗
G1 Dances (Easy version) 1400 binary-search, greedy, two-pointers 1m 39s ✓
G2 Dances (Hard Version) 1900 binary-search, greedy, sortings 2m 32s ✗
Practice › Codeforces Solutions › Codeforces Round 905 (Div. 3) ›

CF 1883G2 - Dances (Hard Version)

We have two arrays of the same size. Before doing anything else, we may reorder each array arbitrarily. An operation removes one element from the first array and one element from the second array.
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CF 1883C - Raspberries

We are given an array and a small integer $k$, where $2 le k le 5$. In one operation we may pick any element and increase it by one. The task is to find the smallest number of operations needed so that the product of all array elements becomes divisible by $k$.
codeforces competitive-programming dp math Jun 8, 2026
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CF 1883F - You Are So Beautiful

We are given an array of integers and are asked to count the number of contiguous subarrays whose elements appear as a subsequence in the original array exactly once.
codeforces competitive-programming data-structures Jun 8, 2026
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CF 1883G1 - Dances (Easy version)

We are given two arrays, a and b, each of size n. We are allowed to remove elements from both arrays in pairs, and before doing so, we can reorder the arrays arbitrarily.
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CF 1883D - In Love

We are asked to maintain a dynamic multiset of segments on the number line, processing additions and deletions one by one. After each operation, we must determine whether the multiset contains at least two segments that do not overlap.
codeforces competitive-programming data-structures greedy Jun 8, 2026
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CF 1883E - Look Back

We are given an array of integers, and our task is to transform it into a non-decreasing sequence using the minimum number of operations. The operation allowed is doubling a single element any number of times.
codeforces competitive-programming bitmasks greedy Jun 8, 2026
Practice › Codeforces Solutions › Codeforces Round 905 (Div. 3) ›

CF 1883A - Morning

We are asked to enter a four-digit PIN on a device where the digits are arranged in a circle from 0 to 9. The cursor starts at 1. Each second, we can either press the current digit or move the cursor to an adjacent digit.
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Practice › Codeforces Solutions › Codeforces Round 905 (Div. 3) ›

CF 1883B - Chemistry

We are asked to determine whether a string can be reduced to a palindrome after removing exactly k characters. The string consists only of lowercase letters, and the number of characters to remove is strictly less than the string length.
codeforces competitive-programming strings Jun 8, 2026