Codeforces Round 995 (Div. 3)

7 problems from Codeforces Round 995 (Div. 3) (contest 2051), difficulty 800-2100. 4/7 solutions verified against sample I/O.

7 items

Codeforces Round 995 (Div. 3)

Div. 3 | 7 problems | 4/7 verified | Difficulty 800-2100 | 16m 34s

#	Problem	Rating	Tags	Accepted	Time	✓
A	Preparing for the Olympiad	800	greedy	35,170	3m 13s	✓
B	Journey	800	binary-search, math	39,743	1m 31s	✓
C	Preparing for the Exam	1000	constructive-algorithms, implementation	28,004	1m 59s	✓
D	Counting Pairs	1200	binary-search, sortings, two-pointers	23,901	1m 19s	✓
E	Best Price	1600	binary-search, brute-force, data-structures	11,951	2m 55s
F	Joker	2000	brute-force, greedy, implementation	4,000	1m 54s
G	Snakes	2100	bitmasks, dp, dsu	2,428	3m 43s

Practice › Codeforces Solutions › Codeforces Round 995 (Div. 3) ›

CF 2051G - Snakes

We are asked to place a set of snakes on a very long 1-dimensional strip of cells. Each snake initially occupies a single cell, and over a sequence of events it can either grow to the right or shrink from the left.

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CF 2051E - Best Price

The algorithm itself is correct. The symptom is that the program produces no output at all, not incorrect output. That means the bug is not in the logic for determining pass/fail. It is in the program structure.

Practice › Codeforces Solutions › Codeforces Round 995 (Div. 3) ›

CF 2051F - Joker

We are working with a deck of cards where only the relative position of a special card, the joker, matters. Initially the joker sits at position m in a line of n cards. Then we perform a sequence of operations.

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CF 2051A - Preparing for the Olympiad

We are given two arrays of length n, one representing how many problems Monocarp can solve on each day, and another representing how many problems Stereocarp would solve on each day if he trains. Monocarp has full freedom to choose any subset of days to train.

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CF 2051D - Counting Pairs

We are given an array of positive integers and a target interval $[x, y]$. We are allowed to remove exactly two distinct elements from the array. After removing them, we look at the sum of what remains, and we want this remaining sum to fall inside the given interval.

Practice › Codeforces Solutions › Codeforces Round 995 (Div. 3) ›

CF 2051C - Preparing for the Exam

There are $n$ possible exam questions. Each available exam version contains all questions except one. The value $ai$ tells us which question is omitted from the $i$-th version. Monocarp knows a set of $k$ questions.

Practice › Codeforces Solutions › Codeforces Round 995 (Div. 3) ›

CF 2051B - Journey

Monocarp is going on a multi-day hike and has a repeating pattern of distances for each day: he walks a kilometers on the first day, b on the second, c on the third, then repeats that cycle indefinitely.