Codeforces Round 481 (Div. 3)

7 problems from Codeforces Round 481 (Div. 3) (contest 978), difficulty 800-1700. 6/7 solutions verified against sample I/O.

7 items

Codeforces Round 481 (Div. 3)

Div. 3 | 7 problems | 6/7 verified | Difficulty 800-1700 | 8m 54s

# Problem Rating Tags Accepted Time ✓
A Remove Duplicates 800 implementation 30,725 1m 22s ✓
B File Name 800 greedy, strings 40,904 1m 13s ✓
C Letters 1000 binary-search, implementation, two-pointers 29,811 1m 12s ✓
D Almost Arithmetic Progression 1500 brute-force, implementation, math 9,952 1m 19s ✓
E Bus Video System 1400 combinatorics, math 10,591 1m 11s ✓
F Mentors 1500 binary-search, data-structures, implementation 9,219 1m 10s ✓
G Petya's Exams 1700 greedy, implementation, sortings 4,881 1m 27s
Practice › Codeforces Solutions › Codeforces Round 481 (Div. 3) ›

CF 978G - Petya's Exams

We are given a timeline of $n$ days and a set of $m$ exams, each fixed to happen on exactly one specific day. Every exam also comes with a preparation window that starts after its announcement day and ends the day before the exam itself, plus a required number of preparation…
codeforces competitive-programming greedy implementation sortings Jun 17, 2026
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CF 978F - Mentors

We are given a set of programmers, each with a fixed skill value. For any programmer $i$, we want to count how many other programmers $j$ they can “mentor”.
codeforces competitive-programming binary-search data-structures implementation Jun 17, 2026
Practice › Codeforces Solutions › Codeforces Round 481 (Div. 3) ›

CF 978D - Almost Arithmetic Progression

We are given a sequence of integers, and we are allowed to slightly “tweak” each element independently by choosing to either decrease it by one, increase it by one, or leave it unchanged.
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Practice › Codeforces Solutions › Codeforces Round 481 (Div. 3) ›

CF 978E - Bus Video System

We are given a sequence of recorded changes in the number of passengers on a bus. Each value tells us how the passenger count changes after a stop, so if we denote the starting number of passengers by $x$, then after each stop we repeatedly add the given deltas and obtain a…
codeforces competitive-programming combinatorics math Jun 17, 2026
Practice › Codeforces Solutions › Codeforces Round 481 (Div. 3) ›

CF 978A - Remove Duplicates

We are given a sequence of integers and asked to compress it by removing duplicates, but with a specific rule: for every distinct value, only its last occurrence in the array must remain.
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Practice › Codeforces Solutions › Codeforces Round 481 (Div. 3) ›

CF 978B - File Name

We are given a short string representing a file name. The only constraint that matters is that the substring "xxx" is forbidden anywhere inside the final string.
codeforces competitive-programming greedy strings Jun 17, 2026
Practice › Codeforces Solutions › Codeforces Round 481 (Div. 3) ›

CF 978C - Letters

We are given several dormitories arranged in a line. Each dormitory contains a known number of rooms, and all rooms across all dormitories are conceptually concatenated into one long sequence.
codeforces competitive-programming binary-search implementation two-pointers Jun 17, 2026