Codeforces Round 587 (Div. 3)

7 problems from Codeforces Round 587 (Div. 3) (contest 1216), difficulty 800-2200. 5/7 solutions verified against sample I/O.

7 items

Codeforces Round 587 (Div. 3)

Div. 3 | 7 problems | 5/7 verified | Difficulty 800-2200 | 19m 54s

# Problem Rating Tags Accepted Time ✓
A Prefixes 800 strings 19,549 2m 38s
B Shooting 900 greedy, implementation, sortings 19,677 2m 12s ✓
C White Sheet 1700 geometry, math 10,357 2m 28s ✓
D Swords 1300 math 12,216 6m 10s
E1 Numerical Sequence (easy version) 1900 binary-search, brute-force, math 3,730 2m 35s ✓
E2 Numerical Sequence (hard version) 2200 binary-search, math 1,651 1m 50s ✓
F Wi-Fi 2100 data-structures, dp, greedy 3,101 2m 1s ✓
Practice › Codeforces Solutions › Codeforces Round 587 (Div. 3) ›

CF 1216D - Swords

We are given a collection of sword types, each type having some remaining count after a theft. For each type $i$, the value $ai$ tells us how many swords of that type are still present in the basement. Originally, every type had the same unknown quantity $x$.
codeforces competitive-programming math Jun 15, 2026
Practice › Codeforces Solutions › Codeforces Round 587 (Div. 3) ›

CF 1216A - Prefixes

We are given a binary string made only of the characters a and b, and its length is guaranteed to be even. The task is to transform this string using the minimum number of single-character flips so that every prefix whose length is even contains exactly the same number of a…
codeforces competitive-programming strings Jun 15, 2026
Practice › Codeforces Solutions › Codeforces Round 587 (Div. 3) ›

CF 1216E1 - Numerical Sequence (easy version)

We are given a conceptual infinite string formed by concatenating blocks of digits. The first block is just the number “1”. The second block is “12”.
codeforces competitive-programming binary-search brute-force math Jun 13, 2026
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CF 1216F - Wi-Fi

We have a line of rooms numbered from 1 to n. Every room must end up connected to the Internet. There are two ways to achieve that. A room can be connected directly, paying a cost equal to its index. Connecting room i directly costs i.
codeforces competitive-programming data-structures dp greedy Jun 11, 2026
Practice › Codeforces Solutions › Codeforces Round 587 (Div. 3) ›

CF 1216E2 - Numerical Sequence (hard version)

The sequence is built by concatenating “blocks”. The first block is just the string “1”. The second block is “12”.
codeforces competitive-programming binary-search math Jun 11, 2026
Practice › Codeforces Solutions › Codeforces Round 587 (Div. 3) ›

CF 1216C - White Sheet

We are given three rectangles on a plane aligned with the axes. The first rectangle is a white sheet, and two subsequent rectangles are black sheets. Each rectangle is defined by its bottom-left and top-right coordinates.
codeforces competitive-programming geometry math Jun 11, 2026
Practice › Codeforces Solutions › Codeforces Round 587 (Div. 3) ›

CF 1216B - Shooting

We are given a line of cans, each with a durability value. Vasya has to shoot all cans exactly once, but the number of shots required to knock down a can depends on how many cans have already been knocked down.
codeforces competitive-programming greedy implementation sortings Jun 11, 2026