Codeforces Round 656 (Div. 3)

4 problems from Codeforces Round 656 (Div. 3) (contest 1385), difficulty 800-2300. 0/4 solutions verified against sample I/O.

4 items

Codeforces Round 656 (Div. 3)

Div. 3 | 4 problems | 0/4 verified | Difficulty 800-2300 | 23m 37s

#	Problem	Rating	Tags	Accepted	Time
B	Restore the Permutation by Merger	800	greedy	39,577	2m 55s
C	Make It Good	1200	greedy	28,910	4m 8s
D	a-Good String	1500	bitmasks, brute-force, divide-and-conquer	21,953	8m 44s
F	Removing Leaves	2300	data-structures, greedy, implementation	2,820	7m 50s

Practice › Codeforces Solutions › Codeforces Round 656 (Div. 3) ›

CF 1385F - Removing Leaves

We are working with a tree where vertices are gradually removed in rounds. In one round, we are allowed to pick a single internal vertex $v$ and remove exactly $k$ of its current leaf neighbors. A vertex counts as a leaf if it has degree one in the current remaining graph.

Practice › Codeforces Solutions › Codeforces Round 656 (Div. 3) ›

CF 1385D - a-Good String

The task is to transform a given string into a very specific recursively defined structure centered around the letter 'a'.

Practice › Codeforces Solutions › Codeforces Round 656 (Div. 3) ›

CF 1385C - Make It Good

We are given an array and we are only allowed to delete a prefix, meaning we remove some number of elements from the front and keep the rest unchanged.

Practice › Codeforces Solutions › Codeforces Round 656 (Div. 3) ›

CF 1385B - Restore the Permutation by Merger

We are given an array of length $2n$. This array was created by taking a permutation $p$ of the numbers $1$ through $n$, making a second copy of the same permutation, and interleaving the two copies while preserving the relative order inside each copy.