COMPFEST 14 - Preliminary Online Mirror (Unrated, ICPC Rules, Teams Preferred)
11 problems from COMPFEST 14 - Preliminary Online Mirror (Unrated, ICPC Rules, Teams Preferred) (contest 1725), difficulty 800-2900. 4/11 solutions verified against sample I/O.
COMPFEST 14 - Preliminary Online Mirror (Unrated, ICPC Rules, Teams Preferred)
ICPC/IOI | 11 problems | 4/11 verified | Difficulty 800-2900 | 39m 12s
| # | Problem | Rating | Tags | Accepted | Time | ✓ |
|---|---|---|---|---|---|---|
| A | Accumulation of Dominoes | 800 | math | 10,130 | 3m 15s | ✓ |
| B | Basketball Together | 1000 | binary-search, greedy, sortings | 28,235 | 1m 59s | ✓ |
| C | Circular Mirror | 2000 | binary-search, combinatorics, geometry | 1,947 | 5m 43s | |
| D | Deducing Sortability | 2900 | binary-search, bitmasks, math | 232 | 4m 6s | |
| F | Field Photography | 2100 | bitmasks, data-structures, sortings | 1,143 | 2m 55s | |
| H | Hot Black Hot White | 1800 | constructive-algorithms, math | 3,009 | 4m 26s | |
| I | Imitating the Key Tree | 2800 | combinatorics, dsu, trees | 298 | 2m 4s | |
| J | Journey | 2500 | dp, trees | 464 | 4m 34s | |
| K | Kingdom of Criticism | 2500 | data-structures, dsu | 780 | 2m 48s | ✓ |
| L | Lemper Cooking Competition | 2400 | data-structures | 1,094 | 4m 20s | |
| M | Moving Both Hands | 1800 | dp, graphs, shortest-paths | 4,383 | 3m 2s | ✓ |
CF 1725J - Journey
We are given a weighted tree where each node represents a city and each edge represents a bidirectional road with a travel time. The traveler must design a walk that eventually visits every city at least once.
CF 1725I - Imitating the Key Tree
Working
CF 1725C - Circular Mirror
We are given a circle with lamps placed on its boundary in a fixed clockwise order. Between consecutive lamps we know the arc lengths, so the geometry of the circle is fully determined up to rotation.
CF 1725F - Field Photography
Each row initially contains a contiguous block of contestants placed on an extremely large integer line of columns. Row $i$ occupies every position from $Li$ to $Ri$, so geometrically each row is just a closed interval.
CF 1725L - Lemper Cooking Competition
We are given a line of stoves, each carrying an integer temperature that may start negative or positive. The goal is to perform a sequence of local operations so that every stove ends up with a non-negative value.
CF 1725M - Moving Both Hands
We are given a directed weighted graph where every edge allows movement in only one direction and has a cost in time. Two tokens, or “hands”, start on different vertices: one is fixed at vertex 1, and the other starts at some vertex p.
CF 1725H - Hot Black Hot White
We are given an array of integers, each representing the strength of a magical stone. We must split these stones into two equal groups and assign each stone one of two colors.
CF 1725D - Deducing Sortability
We are asked to construct a very large hidden array indexed from 1 to N, where N can be up to one billion, without explicitly building it.
CF 1725A - Accumulation of Dominoes
The grid in this problem is not arbitrary, it is completely determined by its dimensions. Every cell contains a unique integer, and the numbers increase row by row from left to right.
CF 1725K - Kingdom of Criticism
We are managing a kingdom with a line of buildings, each with an integer height. Residents occasionally issue criticisms targeting all buildings with heights in a specific interval [l, r], where r-l is always odd.
CF 1725B - Basketball Together
We are asked to form teams from a list of candidate basketball players, each with an integer power. There is an opposing team with power $D$, and a team we form wins if the total power of its members exceeds $D$.