Codeforces Round 141 (Div. 2)

5 problems from Codeforces Round 141 (Div. 2) (contest 228), difficulty 800-2100. 4/5 solutions verified against sample I/O.

5 items

Codeforces Round 141 (Div. 2)

Div. 2 | 5 problems | 4/5 verified | Difficulty 800-2100 | 8m 43s

#	Problem	Rating	Tags	Accepted	Time	✓
A	Is your horseshoe on the other hoof?	800	implementation	139,744	1m 7s	✓
B	Two Tables	1400	brute-force, implementation	3,636	1m 35s	✓
C	Fractal Detector	2000	dp, hashing	549	2m 22s	✓
D	Zigzag	2100	data-structures	438	1m 42s	✓
E	The Road to Berland is Paved With Good Intentions	1900	2-sat, dfs-and-similar, dsu	2,815	1m 57s

Practice › Codeforces Solutions › Codeforces Round 141 (Div. 2) ›

CF 228A - Is your horseshoe on the other hoof?

Valera has exactly four horseshoes. Each horseshoe has a color represented by an integer. For the party, he wants all four horseshoes to have different colors. If some of his horseshoes share the same color, he must buy replacement horseshoes of new colors.

Practice › Codeforces Solutions › Codeforces Round 141 (Div. 2) ›

CF 228D - Zigzag

We maintain an array of up to $10^5$ numbers. Two kinds of operations arrive online. The first operation changes a single array element. The second operation asks for a weighted sum on a segment.

Practice › Codeforces Solutions › Codeforces Round 141 (Div. 2) ›

CF 228E - The Road to Berland is Paved With Good Intentions

We have a graph with n cities connected by m undirected roads. Each road either has asphalt (1) or does not (0). The king can pick a city and the workers will toggle the asphalt status on every road incident to that city: asphalted roads become non-asphalted and vice versa.

Practice › Codeforces Solutions › Codeforces Round 141 (Div. 2) ›

CF 228C - Fractal Detector

We are given an $n times m$ grid where each cell is either white (".") or black (""). Vasya claims to have painted a fractal on some sub-squares of this grid.

Practice › Codeforces Solutions › Codeforces Round 141 (Div. 2) ›

CF 228B - Two Tables

We have two binary matrices. A shift (x, y) means that cell (i, j) of the first matrix is compared with cell (i + x, j + y) of the second matrix. For a fixed shift, the overlap factor is the sum of products of overlapping cells.