National Olympiad in Informatics - Philippines (NOI.PH) Online Eliminations 2020
17 problems from National Olympiad in Informatics - Philippines (NOI.PH) Online Eliminations 2020 (contest 102503), difficulty -. 13/17 solutions verified against sample I/O.
National Olympiad in Informatics - Philippines (NOI.PH) Online Eliminations 2020
Special | 17 problems | 13/17 verified | Difficulty - | 2h 13m
| # | Problem | Rating | Tags | Accepted | Time | ✓ |
|---|---|---|---|---|---|---|
| A | Vincent Adultman | 8m 40s | ✓ | |||
| B | Bogart Gets Disqualified | 2m | ✓ | |||
| C | Partial Reduplication | 4m 34s | ✓ | |||
| D | Union Found | 37m 16s | ✓ | |||
| E | Who Gets Medals | 8m 53s | ||||
| F | Ulam Spiral | 8m 35s | ✓ | |||
| G | Sharing Chocolates 8: The Last Jebediah | 1m 39s | ✓ | |||
| H | A Sheety Problem | 7m 24s | ✓ | |||
| I | Pakain ng Pahiyas 2 | 2m 29s | ✓ | |||
| J | Mildly Irritated Gandhi | 1m 9s | ✓ | |||
| K | Shoedoku | 8m 34s | ||||
| L | Arnis Ball | 9m 32s | ✓ | |||
| M | Se\u00f1orita | 3m 54s | ✓ | |||
| N | Holy Smokes | 12m 23s | ✓ | |||
| O | Gravity Superfight | 1m 46s | ||||
| P | Night Gown | 2m 30s | ||||
| Q | Og and Ug | 11m 51s | ✓ |
CF 102503Q - Og and Ug
We have a rooted tree with node 1 as its root. Each node has an ordered list of children. The program maintains a deque of pairs (node, i), where i tells us which child of that node should be processed next. When a pair is removed from the right end, its node is printed.
CF 102503N - Holy Smokes
The angels define a fixed holiness value for every cigarette. The useful way to look at the process is to forget the angels themselves and examine the binary representation of the cigarette index. Consider cigarette (x), and write (y=x-1).
CF 102503A - Vincent Adultman
We have four people with heights v, a, r, and p. We must choose exactly three of them and stack those three people together. The resulting height is the sum of their three individual heights. The rollercoaster accepts the resulting person if that sum is at least h.
CF 102503F - Ulam Spiral
The grid contains positive integers arranged in a square spiral around 1. The coordinates are centered at 1, with the first coordinate increasing upward and the second increasing to the right. Thus 2 is at (0,1), 3 at (1,1), 4 at (1,0), and so on.
CF 102503P - Night Gown
I can write the editorial, but I need the actual accepted construction/solution idea for Codeforces 102503P - Night Gown to avoid inventing a solution that looks plausible but fails hidden cases.
CF 102503O - Gravity Superfight
I’m sorry, but I can’t provide a reliable complete editorial and implementation for this problem right now. I don’t have enough confidence in the derived game model and data structure details to write a correct solution, and I don’t want to give you a polished-looking…
CF 102503J - Mildly Irritated Gandhi
The islands and bridges form a connected undirected multigraph. Gandhi wants to remove as many bridges as possible while keeping the graph connected.
CF 102503E - Who Gets Medals
I can write this editorial, but the requested artifact is much larger than a single response can fit while still including a complete accepted implementation, full walkthroughs, two worked traces, the provided sample-based assertions, custom tests, and edge-case sections.
CF 102503L - Arnis Ball
We have a line of boxes. Each box stores a number of balls and also has a state: open or closed. The operations modify these two pieces of information together. A flip operation changes every box in a range from open to closed or from closed to open.
CF 102503H - A Sheety Problem
Each sheet can be identified by its smaller page number. Sheet i contains pages i and i+1, so two sheets a and b create a divine pair only when the larger label is at least two greater than the smaller label and the larger sheet appears earlier in the stack.
CF 102503M - Señorita
The input describes two stacks whose shirts are labeled by the day they must be worn. The first stack is listed from bottom to top, and the second stack is listed the same way. The goal is to remove shirts in the order 1, 2, ..., m+n.
CF 102503I - Pakain ng Pahiyas 2
We have n people, each requiring a certain amount of service time ai. There are k independent cashiers. A line is an ordered list of people assigned to one cashier, and a person's waiting time is the total service time of everyone placed before them in that same line.
CF 102503G - Sharing Chocolates 8: The Last Jebediah
The planets form a directed acyclic graph. Each planet has a science value, and every one-way route between planets consumes some amount of fuel. The ship begins at planet 0 and can follow routes as long as the total fuel spent never exceeds the tank capacity V.
CF 102503C - Partial Reduplication
A dish name is built by concatenating three possible pieces: TJ, si, and log. Each occurrence of one piece represents one serving of its corresponding ingredient.
CF 102503K - Shoedoku
We have a rectangular board with j rows and g columns. We need to place p pairs of shoes so that the two shoes in every pair are separated by exactly c cells in one of the four cardinal directions. No cell may contain two shoes.
CF 102503D - Union Found
The logbook describes the state of a factory over time. Before the log begins, we are given every employee together with two ways of identifying them: their full identity, consisting of a title and a name, and their nickname.
CF 102503B - Bogart Gets Disqualified
The chat history is represented by a sequence of usernames. Each username corresponds to one friend who sends the same message, the single character F.