VK Cup 2012 Finals, Practice Session

Solutions for VK Cup 2012 Finals, Practice Session (contest 209). 3/3 problems verified against sample I/O. Difficulty range: 1600-2400.

3 items

VK Cup 2012 Finals, Practice Session

Type: Special | Problems: 3 | Verified: 3/3 | Rating range: 1600-2400 | Time: 11m 47s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Multicolored Marbles	1600	dp, math	5m 3s	✓
B	Pixels	2100	constructive-algorithms, math	1m 41s	✓
C	Trails and Glades	2400	constructive-algorithms, dsu, graphs	5m 3s	✓

Practice › Codeforces Solutions › VK Cup 2012 Finals, Practice Session ›

CF 209A - Multicolored Marbles

Polycarpus has a row of n marbles, each either red or blue, and he wants to count how many subsequences of these marbles form a zebroid, which is a sequence where the colors strictly alternate. A zebroid can be as short as one marble.

Practice › Codeforces Solutions › VK Cup 2012 Finals, Practice Session ›

CF 209B - Pixels

We start with three piles of pixels, one red, one green, and one blue. A fight can only happen between two different colors. When that happens, one pixel survives and immediately changes into the third color.

Practice › Codeforces Solutions › VK Cup 2012 Finals, Practice Session ›

CF 209C - Trails and Glades

The park is an undirected multigraph. Glades are vertices, trails are edges. Self-loops are allowed, and multiple edges between the same pair of vertices are also allowed. Vasya wants to start at vertex 1, traverse every edge exactly once, and return to vertex 1.