Yandex.Algorithm 2011: Qualification 2

Solutions for Yandex.Algorithm 2011: Qualification 2 (contest 82). 4/5 problems verified against sample I/O. Difficulty range: 1100-2600.

5 items

Yandex.Algorithm 2011: Qualification 2

Type: Special | Problems: 5 | Verified: 4/5 | Rating range: 1100-2600 | Time: 11m 32s

Problem Name Rating Tags Solve Time Verified
A Double Cola 1100 implementation, math 1m 30s ✓
B Sets 1700 constructive-algorithms, hashing, implementation 2m 17s ✗
C General Mobilization 2000 data-structures, dfs-and-similar, sortings 2m 42s ✓
D Two out of Three 2000 dp 2m 57s ✓
E Corridor 2600 geometry 2m 6s ✓
Practice › Codeforces Solutions › Yandex.Algorithm 2011: Qualification 2 ›

CF 82A - Double Cola

Five people stand in a queue in a fixed order: Sheldon, Leonard, Penny, Rajesh, Howard. Whenever the person at the front buys a cola, that person immediately creates a copy of themselves, and both copies go to the back of the queue. The queue keeps growing forever.
codeforces competitive-programming implementation math May 28, 2026
Practice › Codeforces Solutions › Yandex.Algorithm 2011: Qualification 2 ›

CF 82B - Sets

We are given all pairwise unions of some hidden disjoint sets. The original sets themselves are not shown. Suppose the hidden sets are $S1, S2, dots, Sn$. For every pair $i neq j$, we are given the set $Si cup Sj$.
codeforces competitive-programming constructive-algorithms hashing implementation May 28, 2026
Practice › Codeforces Solutions › Yandex.Algorithm 2011: Qualification 2 ›

CF 82C - General Mobilization

We have a rooted tree with root at city 1. Every city initially contains exactly one military division. Division i starts in city i and has priority a[i], where a smaller value means higher priority. Each edge has a capacity.
codeforces competitive-programming data-structures dfs-and-similar sortings May 28, 2026
Practice › Codeforces Solutions › Yandex.Algorithm 2011: Qualification 2 ›

CF 82D - Two out of Three

We are asked to simulate a queue of customers, where each customer has a known service time. The cashier can serve two people simultaneously, and the time to serve two people at once is the maximum of their individual times.
codeforces competitive-programming dp May 28, 2026
Practice › Codeforces Solutions › Yandex.Algorithm 2011: Qualification 2 ›

CF 82E - Corridor

We are asked to calculate the area of the floor in a house that is illuminated by two light sources placed symmetrically outside a horizontal strip representing the house.
codeforces competitive-programming geometry May 28, 2026