Technocup 2020 - Elimination Round 2

8 problems from Technocup 2020 - Elimination Round 2 (contest 1225), difficulty 900-3100. 6/8 solutions verified against sample I/O.

8 items

Technocup 2020 - Elimination Round 2

Special | 8 problems | 6/8 verified | Difficulty 900-3100 | 31m 49s

#	Problem	Rating	Tags	Accepted	Time	✓
A	Forgetting Things	900	math	16,621	8m 53s
B1	TV Subscriptions (Easy Version)	1000	implementation	12,518	2m 41s	✓
B2	TV Subscriptions (Hard Version)	1300	implementation, two-pointers	12,194	1m 46s	✓
C	p-binary	1600	bitmasks, brute-force, math	9,787	2m 54s	✓
D	Power Products	1800	hashing, math, number-theory	10,034	3m 50s	✓
E	Rock Is Push	2200	binary-search, dp	2,085	4m 31s	✓
F	Tree Factory	2500	constructive-algorithms, greedy, trees	992	6m 6s
G	To Make 1	3100	bitmasks, constructive-algorithms, dp	659	1m 8s	✓

Practice › Codeforces Solutions › Technocup 2020 - Elimination Round 2 ›

CF 1225F - Tree Factory

We are given a rooted tree where vertex labels already obey a strict ordering constraint: every node except the root has a parent with a smaller label.

Practice › Codeforces Solutions › Technocup 2020 - Elimination Round 2 ›

We are given a sequence of positive integers and asked to count how many pairs of indices produce a product that is a perfect k-th power. In other words, for two distinct elements $ai$ and $aj$, we want to know whether their product can be written as $x^k$ for some integer $x$.

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CF 1225C - p-binary

We are given a positive target number $n$. We also fix an integer $p$, which shifts a family of numbers of the form $2^x + p$, where $x ge 0$. Each such value is a single “building block”, and we are allowed to reuse the same block any number of times.

Practice › Codeforces Solutions › Technocup 2020 - Elimination Round 2 ›

CF 1225A - Forgetting Things

We are asked to construct two positive integers $a$ and $b$ such that they differ by exactly one unit in the sense that $a + 1 = b$. We are not given the numbers themselves. Instead, we are only given the first digit of $a$ and the first digit of $b$.

Practice › Codeforces Solutions › Technocup 2020 - Elimination Round 2 ›

CF 1225E - Rock Is Push

We are walking in a grid from the top-left cell to the bottom-right cell, moving only right or down. The grid is not empty in a passive sense: some cells contain rocks, and those rocks behave dynamically. When we step into a rock cell, the rock does not block us.

Practice › Codeforces Solutions › Technocup 2020 - Elimination Round 2 ›

CF 1225B1 - TV Subscriptions (Easy Version)

We are given a schedule of TV shows over a sequence of days. Each day broadcasts exactly one show, and if we buy a subscription to a show, we gain access to all of its episodes for the entire timeline.

Practice › Codeforces Solutions › Technocup 2020 - Elimination Round 2 ›

CF 1225G - To Make 1

We have a set of $n$ positive integers on a blackboard and a number $k ge 2$. None of the integers is divisible by $k$. We are allowed to repeatedly pick any two numbers $x$ and $y$, erase them, and write $f(x+y)$ instead.

Practice › Codeforces Solutions › Technocup 2020 - Elimination Round 2 ›

CF 1225B2 - TV Subscriptions (Hard Version)

We are given the TV schedule for the next n days. Each day broadcasts an episode from exactly one show, represented by an integer. A subscription is purchased per show, not per episode. If we subscribe to show x, we can watch every occurrence of x in the schedule.

Technocup 2020 - Elimination Round 2

Technocup 2020 - Elimination Round 2

CF 1225F - Tree Factory

CF 1225D - Power Products

CF 1225C - p-binary

CF 1225A - Forgetting Things

CF 1225E - Rock Is Push

CF 1225B1 - TV Subscriptions (Easy Version)

CF 1225G - To Make 1

CF 1225B2 - TV Subscriptions (Hard Version)