Codeforces Round 1075 (Div. 2)

8 problems from Codeforces Round 1075 (Div. 2) (contest 2189), difficulty 800-2800. 0/8 solutions verified against sample I/O.

8 items

Codeforces Round 1075 (Div. 2)

Div. 2 | 8 problems | 0/8 verified | Difficulty 800-2800 | 19m 5s

#	Problem	Rating	Tags	Accepted	Time
A	Table with Numbers	800	greedy, implementation	24,352	4m 12s
B	The Curse of the Frog	1200	constructive-algorithms, greedy, math	15,295	2m 8s
C1	XOR Convenience (Easy Version)	1300	bitmasks, constructive-algorithms, math	13,887	2m 37s
C2	XOR-convenience (Hard Version)			6,203
D1	Little String (Easy Version)	1900	combinatorics, dp, greedy	3,955	2m 6s
D2	Little String (Hard Version)	2200	combinatorics, dp, greedy	1,943	2m 41s
E	Majority Wins?	2600	constructive-algorithms, greedy, math	818	2m 16s
F	Zhora the Vacuum Cleaner	2800	data-structures, dfs-and-similar, dp	227	3m 5s

Practice › Codeforces Solutions › Codeforces Round 1075 (Div. 2) ›

CF 2189F - Zhora the Vacuum Cleaner

We have a tree. Vertex i initially contains ai nuts. There are two kinds of electricity costs. The first cost comes from a special redistribution operation. We choose a vertex v. Then every other vertex is processed from larger distance to smaller distance from v.

Practice › Codeforces Solutions › Codeforces Round 1075 (Div. 2) ›

CF 2189D2 - Little String (Hard Version)

We are not asked to count permutations directly. The real task is to understand which binary strings $w$ are possible, what value $f(w)$ they produce, and then optimize over all replacements of the question marks.

Practice › Codeforces Solutions › Codeforces Round 1075 (Div. 2) ›

CF 2189E - Majority Wins?

We are given a binary string s of length n. Our goal is to transform this string into a single character "1" using a special operation: we can take any contiguous substring, and replace it with the character that occurs at least as many times as the other character in that…

Practice › Codeforces Solutions › Codeforces Round 1075 (Div. 2) ›

CF 2189D1 - Little String (Easy Version)

We are given a string of length $n$ consisting of 0s and 1s. For a permutation $p$ of $[0, 1, dots, n-1]$, the function $f(w)$ counts the number of permutations such that, for each position $i$, the minimum excluded value (MEX) condition is satisfied: if $wi = 1$, there exists…

Practice › Codeforces Solutions › Codeforces Round 1075 (Div. 2) ›

CF 2189A - Table with Numbers

We have an array of numbers. We may select any even number of elements from it and partition them into ordered pairs. A pair (x, y) contributes 1 to the table only if row x and column y exist.

Practice › Codeforces Solutions › Codeforces Round 1075 (Div. 2) ›

CF 2189C1 - XOR Convenience (Easy Version)

We need to construct a permutation of the numbers from 1 to n. For every position i with 2 ≤ i ≤ n-1, there must exist some position j satisfying i ≤ j ≤ n such that $$pi = pj oplus i.$$ Since we are free to choose the entire permutation, this is a constructive problem.

Practice › Codeforces Solutions › Codeforces Round 1075 (Div. 2) ›

CF 2189B - The Curse of the Frog

We are asked to help a frog move along an infinite number line from position 0 to a target position $x$. The frog has $n$ types of magical jumps.