Educational Codeforces Round 143 (Rated for Div. 2)

Solutions for Educational Codeforces Round 143 (Rated for Div. 2) (contest 1795). 2/7 problems verified against sample I/O. Difficulty range: 800-2700.

7 items

Educational Codeforces Round 143 (Rated for Div. 2)

Type: Div. 2 | Problems: 7 | Verified: 2/7 | Rating range: 800-2700 | Time: 15m 29s

Problem Name Rating Tags Solve Time Verified
A Two Towers 800 brute-force, implementation, strings 3m 16s ✗
B Ideal Point 900 brute-force, geometry, greedy 1m 47s ✓
C Tea Tasting 1500 binary-search, data-structures, implementation 2m 56s ✗
D Triangle Coloring 1600 combinatorics, math 1m 46s ✓
E Explosions? 2200 binary-search, data-structures, dp 1m 27s ✗
F Blocking Chips 2400 binary-search, constructive-algorithms, dfs-and-similar 2m 20s ✗
G Removal Sequences 2700 bitmasks, dfs-and-similar, graphs 1m 57s ✗
Practice › Codeforces Solutions › Educational Codeforces Round 143 (Rated for Div. 2) ›

CF 1795F - Blocking Chips

We are given a tree, which is a connected acyclic graph with n vertices. Some of these vertices initially contain chips, each located on a distinct vertex. Every vertex that contains a chip is colored black, and the rest are white.
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CF 1795G - Removal Sequences

We are given a graph with $n$ vertices and $m$ edges. Each vertex $i$ has an associated number $ai$. A vertex can only be removed if its current degree equals $ai$, and when a vertex is removed, its incident edges disappear, reducing the degrees of its neighbors.
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CF 1795E - Explosions?

We are given a row of monsters, each with a certain health, and two types of attacks: a basic spell that reduces any monster's health by 1 for 1 MP, and a single-use "Explosion" that can be targeted on one monster with an arbitrary power.
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CF 1795D - Triangle Coloring

The graph is not arbitrary. It is composed of independent groups of three vertices, and inside each group all three pairs are connected, forming a triangle.
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CF 1795A - Two Towers

We are given two vertical stacks of colored blocks. Each stack is described from bottom to top as a string consisting of only two symbols: B for blue and R for red.
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CF 1795C - Tea Tasting

Connection interrupted. Waiting for the complete answer
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Practice › Codeforces Solutions › Educational Codeforces Round 143 (Rated for Div. 2) ›

CF 1795B - Ideal Point

We are working with a set of closed intervals on a number line, and we are allowed to discard any subset of them. For any integer coordinate $x$, we define its coverage value $f(x)$ as the number of remaining segments that include $x$.
codeforces competitive-programming brute-force geometry greedy Jun 9, 2026