Codeforces Beta Round 62

5 problems from Codeforces Beta Round 62 (contest 68), difficulty 1100-2900. 5/5 solutions verified against sample I/O.

5 items

Codeforces Beta Round 62

Beta | 5 problems | 5/5 verified | Difficulty 1100-2900 | 26m 18s

# Problem Rating Tags Accepted Time ✓
A Irrational problem 1100 implementation, number-theory 5,362 7m 4s ✓
B Energy exchange 1600 binary-search 5,578 7m 4s ✓
C Synchrophasotron 2200 brute-force 353 7m 3s ✓
D Half-decay tree 2500 data-structures, divide-and-conquer, dp 531 2m 50s ✓
E Contact 2900 geometry 84 2m 17s ✓
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CF 68A - Irrational problem

We are asked to count integers $x$ in a given range $[a, b]$ that satisfy a certain remainder-based property. Petya has four distinct integers $p1, p2, p3, p4$.
codeforces competitive-programming implementation number-theory May 28, 2026
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CF 68B - Energy exchange

We have several accumulators, each storing some amount of energy. We are allowed to move energy between them, but every transfer wastes a fixed percentage. If we send x units from one accumulator, the sender loses all x, while the receiver only gains x (100 - k) / 100.
codeforces competitive-programming binary-search May 28, 2026
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CF 68C - Synchrophasotron

We have a directed acyclic graph on vertices 1...n. For every pair i < j, there is exactly one directed edge from i to j. Each pipe has three parameters. It must carry between l and h units of flow inclusive, even if we do not want to use that pipe.
codeforces competitive-programming brute-force May 28, 2026
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CF 68D - Half-decay tree

We have a complete binary tree of height h. Every vertex may store some number of electrons, and queries gradually add more electrons to vertices. A decay operation chooses one leaf uniformly at random and deletes every edge on the path from the root to that leaf.
codeforces competitive-programming data-structures divide-and-conquer dp math probabilities May 28, 2026
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CF 68E - Contact

We are given exactly four triangles. Each triangle represents the shape of one spaceship. A landing platform is just a set of points in the plane, called columns. A ship can land if we can choose three columns that form a triangle congruent to the ship.
codeforces competitive-programming geometry May 28, 2026