Codeforces Round 887 (Div. 1)
F
Panda Meetups
Codeforces
3500
原题
← E→
翻译中…

The red pandas are in town to meet their relatives, the blue pandas! The town is modeled by a number line.

翻译中…

The pandas have already planned their meetup, but the schedule keeps changing. You are given $q$ updates of the form x t c.

翻译中…
  • If $c \lt 0$, it means $|c|$ more red pandas enter the number line at position $x$ and time $t$. Then, each unit of time, they can each independently move one unit in either direction across the number line, or not move at all.
  • If $c \gt 0$, it means that $c$ more blue pandas check position $x$ for red pandas at time $t$. If a blue panda does not meet a red panda at that specific location and time, they dejectedly leave the number line right away. If there is a red panda at a position at the same time a blue panda checks it, they form a friendship and leave the number line. Each red panda can form a friendship with at most one blue panda and vice versa.
翻译中…

The updates will be given in order of non-decreasing $x$ values. After each update, please print the maximum number of friendships if the red pandas move in an optimal order based on all the updates given in the input above (and including) this update.

翻译中…

The order in which a red panda moves can change between updates.

翻译中…

Input

翻译中…

The first line contains $q$ ($1 \leq q \leq 2 \cdot 10^5$)  – the number of updates.

翻译中…

The $i$-th line of the next $q$ lines consists of $3$ integers $x_i$, $t_i$ and $c_i$ ($0 \leq x_i \leq 10^9$, $0 \leq t_i \leq 10^9$, $0 \lt |c_i| \leq 1000$) – the description of the $i$-th update.

翻译中…

It is guaranteed that the $x_i$ will be given in non-decreasing order.

翻译中…

Output

翻译中…

After each update, print the maximum number of friendships that can be formed.

翻译中…

Note

翻译中…

In the first example, the number of friendships after each update can be optimized as follows:

翻译中…
  1. $3$ blue pandas now check for red pandas at position $0$ at time $6$. There are no red pandas anywhere, so there are no friendships.
  2. $5$ red pandas now appear at position $4$ and time $2$. $4$ of the red pandas can travel to position $0$ at time $6$, where $3$ of them can make friendships with the $3$ existing blue pandas.
  3. $6$ red pandas now appear at position $7$ and time $4$. No new blue pandas are added, so the maximum number of friendships is still $3$.
  4. $100$ blue pandas now appear at position $10$ and time $5$. No red pandas can reach them at a time of $5$, so no new friendships are created.
  5. $7$ blue pandas now appear at position $10$ and time $8$. $6$ of the red pandas at position $7$ and time $4$, along with $1$ red panda at position $4$ and time $2$, can reach $7$ of the blue pandas at position $10$ at time $8$, adding $7$ new friendships. This brings the total to $10$ friendships.
翻译中…

样例

Input #1
5
0 6 3
4 2 -5
7 4 -6
10 5 100
10 8 7
Output #1
0
3
3
3
10
InputCopy OutputCopy
Input #2
5
0 6 3
4 2 -5
7 4 -6
10 5 100
11 8 7
Output #2
0
3
3
3
9
InputCopy OutputCopy
Input #3
7
0 8 6
2 7 -2
3 1 -6
5 3 -8
7 3 -3
8 0 -2
8 2 1
Output #3
0
0
6
6
6
6
7
InputCopy OutputCopy
Input #4
4
0 0 -3
0 0 2
0 0 4
0 0 -10
Output #4
0
2
3
6
InputCopy OutputCopy
题目信息
题号
1852F
时间限制
4 s
内存限制
256 MB
标签
数据结构
动态规划
网络流

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。