Codeforces Round 277.5 (Div. 2)

6 problems from Codeforces Round 277.5 (Div. 2) (contest 489), difficulty 1200-2300. 4/6 solutions verified against sample I/O.

6 items

Codeforces Round 277.5 (Div. 2)

Div. 2 | 6 problems | 4/6 verified | Difficulty 1200-2300 | 12m 13s

#	Problem	Rating	Tags	Accepted	Time	✓
A	SwapSort	1200	greedy, implementation, sortings	10,585	2m 34s
B	BerSU Ball	1200	dfs-and-similar, dp, graph-matchings	56,718	2m 3s	✓
C	Given Length and Sum of Digits...	1400	dp, greedy, implementation	51,664	1m 25s	✓
D	Unbearable Controversy of Being	1700	brute-force, combinatorics, dfs-and-similar	7,048	1m 53s	✓
E	Hiking	2300	binary-search, dp	1,146	2m 38s
F	Special Matrices	2100	combinatorics, dp	1,939	1m 40s	✓

Practice › Codeforces Solutions › Codeforces Round 277.5 (Div. 2) ›

CF 489E - Hiking

We have a sequence of resting points along a river. Point i is located at position x[i] and has picturesqueness value b[i]. The traveler starts at coordinate 0 and must finish at the last resting point, which is also the farthest one.

Practice › Codeforces Solutions › Codeforces Round 277.5 (Div. 2) ›

CF 489F - Special Matrices

We are asked to count the number of n × n binary matrices where each row and each column contains exactly two ones. Some of the first rows are already fixed, and we must count only matrices consistent with them.

Practice › Codeforces Solutions › Codeforces Round 277.5 (Div. 2) ›

CF 489D - Unbearable Controversy of Being

We are given a directed graph representing intersections and one-way roads. A "damn rhombus" consists of four distinct vertices $a, b, c, d$ such that there are directed edges $$a rightarrow b,quad b rightarrow c,quad a rightarrow d,quad d rightarrow c$$ In other words, from…

Practice › Codeforces Solutions › Codeforces Round 277.5 (Div. 2) ›

CF 489A - SwapSort

We are given an array of integers and must transform it into non-decreasing order by performing swaps of array positions. The interesting part is that we do not need the minimum number of swaps. Any valid sequence containing at most n swaps is accepted.

Practice › Codeforces Solutions › Codeforces Round 277.5 (Div. 2) ›

CF 489B - BerSU Ball

We have two groups of dancers. Each boy has a skill level, and each girl has a skill level. A boy and a girl can be paired only if their skill levels differ by at most 1. Every dancer can belong to at most one pair. The task is to form as many valid boy-girl pairs as possible.

Practice › Codeforces Solutions › Codeforces Round 277.5 (Div. 2) ›

CF 489C - Given Length and Sum of Digits...

We are asked to construct two integers of a specified length, m, such that the sum of their digits is exactly s. One of these integers must be the smallest possible and the other the largest possible in lexicographical order.