Educational Codeforces Round 71 (Rated for Div. 2)

7 problems from Educational Codeforces Round 71 (Rated for Div. 2) (contest 1207), difficulty 800-2700. 3/7 solutions verified against sample I/O.

7 items

Educational Codeforces Round 71 (Rated for Div. 2)

Div. 2 | 7 problems | 3/7 verified | Difficulty 800-2700 | 19m 27s

# Problem Rating Tags Accepted Time ✓
A There Are Two Types Of Burgers 800 brute-force, greedy, implementation 23,387 2m 58s ✓
B Square Filling 1200 constructive-algorithms, greedy, implementation 13,758 1m 56s ✓
C Gas Pipeline 1500 dp, greedy 10,442 2m 36s
D Number Of Permutations 1800 combinatorics 6,699 3m 4s
E XOR Guessing 1900 bitmasks, interactive, math 6,654 3m 8s
F Remainder Problem 2100 brute-force, data-structures, implementation 6,747 1m 35s ✓
G Indie Album 2700 data-structures, dfs-and-similar, hashing 1,225 4m 10s
Practice › Codeforces Solutions › Educational Codeforces Round 71 (Rated for Div. 2) ›

CF 1207G - Indie Album

We are given a growing collection of strings, where each new string is either a single character or an old string extended by exactly one character at the end.
codeforces competitive-programming data-structures dfs-and-similar hashing string-suffix-structures strings trees Jun 15, 2026
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CF 1207E - XOR Guessing

We are playing an interactive guessing game where a hidden number $x$ is fixed in advance, and it lies in the range from $0$ to $2^{14}-1$. We are allowed to ask up to two questions.
codeforces competitive-programming bitmasks interactive math Jun 15, 2026
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CF 1207D - Number Of Permutations

We are given a collection of $n$ labeled tiles, where each tile carries a pair of integers $(ai, bi)$. Our task is to count how many ways we can reorder these tiles such that the resulting sequence avoids two very specific failure patterns.
codeforces competitive-programming combinatorics Jun 15, 2026
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CF 1207C - Gas Pipeline

We are building a linear structure along a road that is represented as a binary string. Each position corresponds to a unit segment of road. A 0 means normal road, while a 1 means a crossroad where the pipeline must be lifted. The pipeline normally runs at height 1.
codeforces competitive-programming dp greedy Jun 15, 2026
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CF 1207A - There Are Two Types Of Burgers

We are given a small restaurant model where each query describes available ingredients and selling prices for two kinds of burgers. One burger requires buns plus beef, the other requires buns plus chicken.
codeforces competitive-programming brute-force greedy implementation math Jun 13, 2026
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CF 1207F - Remainder Problem

We are maintaining a very large array indexed from 1 to 500000, initially all zeros, and we support two operations. The first operation adds a value to a single position.
codeforces competitive-programming brute-force data-structures implementation Jun 11, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 71 (Rated for Div. 2) ›

CF 1207B - Square Filling

We are working with a binary grid transformation problem. There is a target grid A filled with zeros and ones, and a second grid B which starts completely empty.
codeforces competitive-programming constructive-algorithms greedy implementation Jun 11, 2026