Codeforces Round 166 (Div. 2)

Solutions for Codeforces Round 166 (Div. 2) (contest 271). 3/4 problems verified against sample I/O. Difficulty range: 1300-2200.

4 items

Codeforces Round 166 (Div. 2)

Type: Div. 2 | Problems: 4 | Verified: 3/4 | Rating range: 1300-2200 | Time: 7m 9s

Problem	Name	Rating	Tags	Solve Time	Verified
B	Prime Matrix	1300	binary-search, brute-force, math	1m 46s	✓
C	Secret	1500	constructive-algorithms, implementation	1m 31s	✗
D	Good Substrings	1800	data-structures, strings	1m 42s	✓
E	Three Horses	2200	constructive-algorithms, math, number-theory	2m 10s	✓

Practice › Codeforces Solutions › Codeforces Round 166 (Div. 2) ›

CF 271B - Prime Matrix

We are given a rectangular grid of integers. In one operation we may pick any single cell and increase its value by exactly one. We can repeat this as many times as we want on any cells. The goal is not to make the whole matrix prime.

Practice › Codeforces Solutions › Codeforces Round 166 (Div. 2) ›

CF 271C - Secret

We are asked to distribute a collection of n words among k Keepers in such a way that every Keeper receives a subset of words satisfying three conditions. First, no two Keepers can share a word. Second, every word must be assigned to some Keeper.

Practice › Codeforces Solutions › Codeforces Round 166 (Div. 2) ›

CF 271D - Good Substrings

We are given a lowercase string and a classification of the 26 English letters into two groups, good and bad. A substring is considered valid if it contains at most k bad characters. Among all such valid substrings, we must count how many different strings appear.

Practice › Codeforces Solutions › Codeforces Round 166 (Div. 2) ›

CF 271E - Three Horses

We start with exactly one card (x, y) where 1 ≤ x < y ≤ m. Three operations are available. The gray horse increases both numbers by one: (a, b) → (a + 1, b + 1). The white horse works only when both numbers are even: (a, b) → (a / 2, b / 2).