WC '17 Contest 2 S3 - Battle of the Pelennor Fields - Olympiads Online Judge

WC '17 Contest 2 S3 - Battle of the Pelennor Fields

Points: 12 (partial)

Time limit: 2.75s

Memory limit: 128M

Author:

SourSpinach

Problem type

Woburn Challenge 2017-18 Round 2 - Senior Division

An enormous, decisive battle is about to take place on the Pelennor Fields before the city of Minas Tirith! A noble army of Gondorian men will engage in battle against Sauron's evil army of orcs in an attempt to save their home and all of Middle Earth. Gandalf has given you your own vital task - not to actually participate in combat, but to report to him the state of the battle as it unfolds.

The battlefield can be represented as an infinite number line, and is initially empty. $N$ $N$ $(1 \le N \le 300\,000)$ $(1 \leq N \leq 300 000)$ events will then occur over the course of the battle, one after another. The $i^{th}$ $i^{t h}$ event's type is indicated by the value $E_i$ $E_{i}$ $(1 \le E_i \le 2)$ $(1 \leq E_{i} \leq 2)$ :

If $E_i = 1$ $E_{i} = 1$ , then an orc arrives on the battlefield at position $O_i$ $O_{i}$ $(0 \le O_i \le 10^9)$ $(0 \leq O_{i} \leq 10^{9})$ .
Otherwise, if $E_i = 2$ $E_{i} = 2$ , then a Gondorian archer arrives on the battlefield at position $A_i$ $A_{i}$ $(0 \le A_i \le 10^9)$ $(0 \leq A_{i} \leq 10^{9})$ , and having a bow range of $R_i$ $R_{i}$ $(1 \le R_i \le 10^9)$ $(1 \leq R_{i} \leq 10^{9})$ . Such an archer is able to shoot any orcs which are at most $R_i$ $R_{i}$ units of distance away from $A_i$ $A_{i}$ .

All $N$ $N$ combatants' positions are distinct.

An orc is "vulnerable" if there's at least one archer on the battlefield who is able to shoot that orc. After each of the $N$ $N$ events, you'd like to report to Gandalf the number of orcs currently on the battlefield which are not vulnerable.

Subtasks

In test cases worth $4/27$ $4 / 27$ of the points, $N \le 1000$ $N \leq 1000$ and $R_i = 1$ $R_{i} = 1$ for each applicable $i$ $i$ .
In test cases worth another $4/27$ $4 / 27$ of the points, $R_i = 1$ $R_{i} = 1$ for each applicable $i$ $i$ .
In test cases worth another $8/27$ $8 / 27$ of the points, $R_i = 10^6$ $R_{i} = 10^{6}$ for each applicable $i$ $i$ .

Input Specification

The first line of input consists of a single integer, $N$ $N$ .
$N$ $N$ lines follow, the $i^{th}$ $i^{t h}$ of which consists of a single integer, $E_i$ $E_{i}$ , followed by either $1$ $1$ more integer $O_i$ $O_{i}$ (if $E_i = 1$ $E_{i} = 1$ ) or $2$ $2$ more integers $A_i$ $A_{i}$ and $R_i$ $R_{i}$ (if $E_i = 2$ $E_{i} = 2$ ), for $i = 1 \dots N$ $i = 1 \dots N$ .

Output Specification

Output $N$ $N$ lines, the $i^{th}$ $i^{t h}$ of which should consist of a single integer, the number of non-vulnerable orcs on the battlefield after the first $i$ $i$ events.

Sample Input

Copy

Sample Output

Copy

Sample Explanation

After the $2^{nd}$ $2^{n d}$ event, there are still no archers on the field, meaning that both orcs are non-vulnerable. After the $3^{rd}$ $3^{r d}$ event, the newly-arrived archer is just barely able to shoot the first orc, while the second orc is too far away and so is still non-vulnerable. After the $7^{th}$ $7^{t h}$ event, the orcs at positions $22$ $22$ and $23$ $23$ are still non-vulnerable, while the remaining $3$ $3$ orcs are vulnerable.

Comments

2

cabbagecabbagecabbage commented on July 13, 2021, 4:05 p.m. ← edited →

thanks a lot. can't believe i didnt try using a custom hash in the 10 hours of optimizing...

edit: oops didnt click reply

1

Nils_Emmenegger commented on July 13, 2021, 5:21 p.m.

TIL about custom hash functions. Thanks for the link!

3

Nils_Emmenegger commented on July 13, 2021, 5:47 a.m. ← edited →

Coordinate compression with a gp_hash_table dies on this question for some reason, switch it out for an unordered_map or map (or another coord compression method entirely, or another solution that doesn't even use coord compression) to get your solution to pass if you're running into this.