Educational Codeforces Round 98 (Rated for Div. 2)

Solutions for Educational Codeforces Round 98 (Rated for Div. 2) (contest 1452). 5/7 problems verified against sample I/O. Difficulty range: 800-2900.

7 items

Educational Codeforces Round 98 (Rated for Div. 2)

Type: Div. 2 | Problems: 7 | Verified: 5/7 | Rating range: 800-2900 | Time: 30m 52s

Problem Name Rating Tags Solve Time Verified
A Robot Program 800 math 1m 22s ✓
B Toy Blocks 1400 binary-search, greedy, math 5m 26s ✓
C Two Brackets 800 greedy 8m 21s ✓
D Radio Towers 1600 combinatorics, dp, math 1m 31s ✓
E Two Editorials 2500 brute-force, dp, greedy 1m 27s ✓
F Divide Powers 2900 constructive-algorithms, greedy 1m 54s ✗
G Game On Tree 2700 data-structures, dfs-and-similar, greedy 10m 51s ✗
Practice › Codeforces Solutions › Educational Codeforces Round 98 (Rated for Div. 2) ›

CF 1452G - Game On Tree

I see exactly what went wrong in the previous implementation. The problem is subtle: the “all equal” case [1, 1, 1] fails because the formula incorrectly tries to round the sum to the next multiple of n-1 even when the current sum is already enough to satisfy the maxa…
codeforces competitive-programming data-structures dfs-and-similar greedy trees Jun 11, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 98 (Rated for Div. 2) ›

CF 1452C - Two Brackets

Ah, now I see exactly why the previous solution produced wrong output. The earlier code assumes that every digit exists on the board and adds a maximal area even when the digit does not exist at all, or when it occurs in multiple rows and columns without considering the…
codeforces competitive-programming greedy Jun 11, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 98 (Rated for Div. 2) ›

CF 1452F - Divide Powers

We are given a collection of numbers where every element is a power of two. Instead of listing them explicitly, the input tells us how many copies we have of each value $2^i$. Think of it as a multiset where level $i$ contributes $cnti$ identical tokens, each worth $2^i$.
codeforces competitive-programming constructive-algorithms greedy Jun 11, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 98 (Rated for Div. 2) ›

CF 1452B - Toy Blocks

We are given a set of boxes, each containing a certain number of toy blocks. The game consists of a child choosing a single box and attempting to redistribute all its blocks evenly across the other boxes.
codeforces competitive-programming binary-search greedy math sortings Jun 11, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 98 (Rated for Div. 2) ›

CF 1452E - Two Editorials

We are given a problemset of n problems and m participants. Each participant is interested in a specific contiguous range of problems, defined by [li, ri]. Two authors are going to present tutorials, each covering exactly k consecutive problems.
codeforces competitive-programming brute-force dp greedy sortings two-pointers Jun 11, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 98 (Rated for Div. 2) ›

CF 1452D - Radio Towers

We have a line of $n + 2$ towns, numbered from $0$ to $n + 1$, positioned at consecutive integer coordinates. Towns $1$ through $n$ may independently receive a radio tower, each with probability $frac{1}{2}$.
codeforces competitive-programming combinatorics dp math Jun 11, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 98 (Rated for Div. 2) ›

CF 1452A - Robot Program

We have a robot standing at the origin of an infinite 2D grid, and we need to guide it to a target cell with coordinates $(x, y)$. The robot can move north, east, south, west, or stay in place, but it cannot repeat the same command consecutively.
codeforces competitive-programming math Jun 11, 2026