Codeforces Round 876 (Div. 2)
B
Lamps
Codeforces
1100
原题
← AC →
翻译中…

You have $n$ lamps, numbered by integers from $1$ to $n$. Each lamp $i$ has two integer parameters $a_i$ and $b_i$.

翻译中…

At each moment each lamp is in one of three states: it may be turned on, turned off, or broken.

翻译中…

Initially all lamps are turned off. In one operation you can select one lamp that is turned off and turn it on (you can't turn on broken lamps). You receive $b_i$ points for turning lamp $i$ on. The following happens after each performed operation:

翻译中…
  • Let's denote the number of lamps that are turned on as $x$ (broken lamps do not count). All lamps $i$ such that $a_i \le x$ simultaneously break, whether they were turned on or off.
翻译中…

Please note that broken lamps never count as turned on and that after a turned on lamp breaks, you still keep points received for turning it on.

翻译中…

You can perform an arbitrary number of operations.

翻译中…

Find the maximum number of points you can get.

翻译中…

Input

翻译中…

The first line contains a single integer $t$ ($1 \le t \le 10^4$) — the number of test cases.

翻译中…

The first line contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$) — the number of lamps.

翻译中…

Each of the next $n$ lines contains two integers $a_i$ and $b_i$ ($1 \le a_i \le n, 1 \le b_i \le 10^9$) — parameters of the $i$-th lamp.

翻译中…

It is guaranteed that sum of $n$ over all test cases doesn't exceed $2 \cdot 10^5$.

翻译中…

Output

翻译中…

For each test case, output one integer — the maximum number of points you can get.

翻译中…

Note

翻译中…

In first test case $n = 4$. One of ways to get the maximum number of points is as follows:

翻译中…
  • You turn lamp $4$ on and receive $b_4 = 13$ points.
  • The number of lamps that are turned on is $1$, so all lamps with $a_i \le 1$ (namely lamps $2$, $3$ and $4$) break. Lamp $4$ is no longer turned on, so the number of lamps that are turned becomes $0$.
  • The only lamp you can turn on is lamp $1$, as all other lamps are broken. You receive $b_1 = 2$ points for turning it on.
  • The number of lamps that are turned on is $1$. As $a_1 = 2$, lamp $1$ doesn't break.
翻译中…

Your receive $13 + 2 = 15$ points in total. It can be shown that this is the maximum number of points you can get, so the answer for the first test case is $15$.

翻译中…

In the second test case, one of the ways to get the maximum number of points is as follows:

翻译中…
  • On the first operation you turn on lamp $4$ and receive $2$ points. No lamps break after the first operation.
  • On the second operation you turn on lamp $3$ and receive $5$ points. After the second operation, there are $2$ lamps turned on. As $a_3 \le 2$, lamp $3$ breaks.
  • On the third operation, you turn on lamp $1$ and receive $4$ points.
  • On the fourth operation, you turn on lamp $5$ and receive $3$ points. After that there are $3$ lamps turned on: lamps $1$, $4$ and $5$. Lamps $1$, $2$, $4$ and $5$ simultaneously break, because for all of them $a_i \le 3$.
翻译中…

You receive $2 + 5 + 4 + 3 = 14$ points in total. It can be shown that this is the maximum number of points you can get.

翻译中…

In the third test case, one of the ways to get the maximum number of points is as follows:

翻译中…
  • Turn the lamp $3$ on and receive $4$ points. Lamps $1$ and $3$ break.
  • Turn the lamp $2$ on and receive $4$ points.
  • Turn the lamp $6$ on and receive $3$ points. Lamp $6$ breaks.
  • Turn the lamp $4$ on and receive $4$ points.
  • Turn the lamp $5$ on and receive $5$ points. Lamps $2$, $4$ and $5$ break.
翻译中…

You receive $4 + 4 + 3 + 4 + 5 = 20$ points in total. It can be shown that this is the maximum number of points you can get.

翻译中…

样例

Input #1
4
4
2 2
1 6
1 10
1 13
5
3 4
3 1
2 5
3 2
3 3
6
1 2
3 4
1 4
3 4
3 5
2 3
1
1 1
Output #1
15
14
20
1
InputCopy OutputCopy
题目信息
题号
1839B
时间限制
1 s
内存限制
256 MB
标签
贪心
排序

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。