Educational Codeforces Round 142 (Rated for Div. 2)

Solutions for Educational Codeforces Round 142 (Rated for Div. 2) (contest 1792). 3/7 problems verified against sample I/O. Difficulty range: 800-2900.

7 items

Educational Codeforces Round 142 (Rated for Div. 2)

Type: Div. 2 | Problems: 7 | Verified: 3/7 | Rating range: 800-2900 | Time: 17m 54s

Problem	Name	Rating	Tags	Solve Time	Verified
A	GamingForces	800	greedy, sortings	2m 33s	✗
B	Stand-up Comedian	1200	greedy, math	2m 5s	✗
C	Min Max Sort	1500	binary-search, brute-force, greedy	4m 53s	✗
D	Fixed Prefix Permutations	1700	binary-search, bitmasks, data-structures	2m 6s	✗
E	Divisors and Table	2400	brute-force, dfs-and-similar, dp	1m 30s	✓
F1	Graph Coloring (easy version)	2700	combinatorics, dp, graphs	3m 19s	✓
F2	Graph Coloring (hard version)	2900	brute-force, combinatorics, divide-and-conquer	1m 28s	✓

Practice › Codeforces Solutions › Educational Codeforces Round 142 (Rated for Div. 2) ›

CF 1792F1 - Graph Coloring (easy version)

We are asked to count the number of ways to color the edges of a complete graph on $n$ vertices using exactly two colors, red and blue, under very specific connectivity constraints. A complete graph means every vertex is connected to every other vertex.

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CF 1792F2 - Graph Coloring (hard version)

We are asked to color the edges of a complete graph with two colors, red and blue. Each edge must receive exactly one color. The crucial constraint is connectivity: every subset of vertices of size at least two must be connected in exactly one color, either red or blue.

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CF 1792C - Min Max Sort

We are given a permutation of size $n$, which is simply a sequence containing each integer from $1$ to $n$ exactly once. The task is to sort this permutation using a special operation any number of times.

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CF 1792D - Fixed Prefix Permutations

We are given multiple permutations of length $m$. Each permutation contains all integers from 1 to $m$ exactly once. The "beauty" of a permutation is the length of its initial prefix that forms the identity sequence $1, 2, 3, dots, k$.

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CF 1792E - Divisors and Table

We are working with an $n times n$ multiplication table where each cell $(i, j)$ contains the value $i cdot j$. This table is not constructed explicitly; instead, we reason about which numbers appear in it. For each test case, we are given a number $m = m1 cdot m2$.

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CF 1792A - GamingForces

We are asked to determine the minimum number of spell casts Monocarp needs to kill a set of monsters, each with a certain health value.

Practice › Codeforces Solutions › Educational Codeforces Round 142 (Rated for Div. 2) ›

CF 1792B - Stand-up Comedian

We are given a fixed audience of two people whose reactions to jokes are completely determined by joke type. Each joke changes each person’s mood by either increasing it by one if they like the joke or decreasing it by one if they do not.