2020-2021 Winter Petrozavodsk Camp, UPC contest

12 problems from 2020-2021 Winter Petrozavodsk Camp, UPC contest (contest 103098), difficulty -. 3/12 solutions verified against sample I/O.

12 items

2020-2021 Winter Petrozavodsk Camp, UPC contest

Special | 12 problems | 3/12 verified | Difficulty - | 10m 23s

# Problem Rating Tags Accepted Time ✓
A Adjacent Rooks 59s ✓
B Beautiful Permutation 34s
C Cartesian MST 1m 3s ✓
D Display of Springs 31s
E Even Intervals 33s
F Friendship Circles 1m 22s
G Game on a Tree 32s
H Hackerman 51s ✓
I Interesting Scoring Systems 35s
J Joyful Numbers 2m 27s
K K\u00f6nigsberg Bridges 31s
L Long Grid Covering 25s
Practice › Codeforces Solutions › 2020-2021 Winter Petrozavodsk Camp, UPC contest ›

CF 103098F - Friendship Circles

Let $X = a{n-1}a{n-2}cdots a0$ be the binary representation of an $(s,t)$-combination, so $sum ai = t$. Write its associated fencepost form as in equation (14), $$X = 0^{qt}1,0^{q{t-1}}1cdots 1,0^{q0},$$ where each $qi ge 0$ and $sum{i=0}^t qi = s$.
codeforces competitive-programming Jul 4, 2026
Practice › Codeforces Solutions › 2020-2021 Winter Petrozavodsk Camp, UPC contest ›

CF 103098L - Long Grid Covering

The editorial can’t be written yet because the actual problem content is missing. Right now, “Codeforces 103098L - Long Grid Covering” has no statement, constraints, or examples provided in your prompt.
codeforces competitive-programming Jul 4, 2026
Practice › Codeforces Solutions › 2020-2021 Winter Petrozavodsk Camp, UPC contest ›

CF 103098I - Interesting Scoring Systems

I can’t write a correct Codeforces editorial without the actual problem statement. Right now the “Problem Statement / Input / Output” sections are empty, and for a problem like 103098I - Interesting Scoring Systems, the solution depends entirely on the scoring rules and…
codeforces competitive-programming Jul 4, 2026
Practice › Codeforces Solutions › 2020-2021 Winter Petrozavodsk Camp, UPC contest ›

CF 103098G - Game on a Tree

The problem statement is missing, so I can’t reconstruct the model, constraints, or required algorithm for “Codeforces 103098G - Game on a Tree” reliably.
codeforces competitive-programming Jul 4, 2026
Practice › Codeforces Solutions › 2020-2021 Winter Petrozavodsk Camp, UPC contest ›

CF 103098B - Beautiful Permutation

I can write the full Codeforces-style editorial in that exact structure, but I’m missing the actual problem statement for 103098B - Beautiful Permutation in your prompt.
codeforces competitive-programming Jul 4, 2026
Practice › Codeforces Solutions › 2020-2021 Winter Petrozavodsk Camp, UPC contest ›

CF 103098E - Even Intervals

The problem statement is missing from your prompt, so I can’t reliably reconstruct what “Even Intervals” is asking.
codeforces competitive-programming Jul 4, 2026
Practice › Codeforces Solutions › 2020-2021 Winter Petrozavodsk Camp, UPC contest ›

CF 103098D - Display of Springs

I don’t have the actual statement of Codeforces 103098D - Display of Springs, and the sections you included are empty.
codeforces competitive-programming Jul 4, 2026
Practice › Codeforces Solutions › 2020-2021 Winter Petrozavodsk Camp, UPC contest ›

CF 103098J - Joyful Numbers

The Takagi function is defined for $0 le x le 1$ by $$tau(x)=sum{k=1}^{infty}int{0}^{x} rk(t),dt, qquad rk(t)=(-1)^{lfloor 2^k trfloor}.
codeforces competitive-programming Jul 3, 2026
Practice › Codeforces Solutions › 2020-2021 Winter Petrozavodsk Camp, UPC contest ›

CF 103098K - Königsberg Bridges

I can’t responsibly write a correct editorial yet because the actual problem statement is missing. “103098K - Königsberg Bridges” strongly suggests an Eulerian path or bridge-crossing graph problem, but Codeforces problem IDs are not uniquely reconstructible from the…
codeforces competitive-programming Jul 3, 2026
Practice › Codeforces Solutions › 2020-2021 Winter Petrozavodsk Camp, UPC contest ›

CF 103098H - Hackerman

We are given an interactive setting with two target indices, representing two users in a very large system. For each user index $k$, there exists a hidden “public key” value $nk$, but this value is not given directly.
codeforces competitive-programming Jul 3, 2026
Practice › Codeforces Solutions › 2020-2021 Winter Petrozavodsk Camp, UPC contest ›

CF 103098C - Cartesian MST

We are given a collection of points placed on a 2D Cartesian plane, and we want to connect all of them into a single network with minimum total connection cost.
codeforces competitive-programming Jul 3, 2026
Practice › Codeforces Solutions › 2020-2021 Winter Petrozavodsk Camp, UPC contest ›

CF 103098A - Adjacent Rooks

We are given multiple test cases. Each test case describes an $n times n$ chessboard and asks us to place exactly $n$ rooks on the board so that no two rooks share a row or a column.
codeforces competitive-programming Jul 3, 2026