Codeforces Round 899 (Div. 2)
C
Card Game
Codeforces
1500
原题
← BD →
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There are $n$ cards stacked in a deck. Initially, $a_{i}$ is written on the $i$-th card from the top. The value written on a card does not change.

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You will play a game. Initially your score is $0$. In each turn, you can do one of the following operations:

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  • Choose an odd$^{\dagger}$ positive integer $i$, which is not greater than the number of cards left in the deck. Remove the $i$-th card from the top of the deck and add the number written on the card to your score. The remaining cards will be reindexed starting from the top.
  • Choose an even$^{\ddagger}$ positive integer $i$, which is not greater than the number of cards left in the deck. Remove the $i$-th card from the top of the deck. The remaining cards will be reindexed starting from the top.
  • End the game. You can end the game whenever you want, you do not have to remove all cards from the initial deck.
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What is the maximum score you can get when the game ends?

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$^{\dagger}$ An integer $i$ is odd, if there exists an integer $k$ such that $i = 2k + 1$.

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$^{\ddagger}$ An integer $i$ is even, if there exists an integer $k$ such that $i = 2k$.

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Input

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Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^{4}$). The description of the test cases follows.

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The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^{5}$).

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The second line of each test case contains $n$ integers $a_1, a_2, \ldots, a_n$ ($-10^{9} \le a_i \le 10^{9}$).

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It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^{5}$.

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Output

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For each test case, print a single integer — the maximum score you can get when the game ends.

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Note

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In the first test case, one can get the score of $5$ as follows:

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  1. In the first turn, choose $i=2$. Your score remains $0$ and the numbers written on the cards from the top will become $[-4, -3, 5]$.
  2. In the second turn, choose $i=3$. Your score will become $5$ and the numbers written on the cards from the top will become $[-4, -3]$.
  3. In the third turn, end the game with the score of $5$.
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In the second test case, one can get the score of $4$ as follows:

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  1. In the first turn, choose $i=3$. Your score will become $3$ and the numbers written on the cards from the top will become $[1, -2, -4]$.
  2. In the second turn, choose $i=1$. Your score will become $4$ and the numbers written on the cards from the top will become $[-2, -4]$.
  3. In the third turn, end the game with the score of $4$.
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In the third test case, one can get the score of $2$ as follows:

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  1. In the first turn, choose $i=1$. Your score will become $-1$ and the numbers written on the cards from the top will become $[3, -5]$.
  2. In the second turn, choose $i=1$. Your score will become $2$ and the numbers written on the cards from the top will become $[-5]$.
  3. In the third turn, end the game with the score of $2$.
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样例

Input #1
4
4
-4 1 -3 5
4
1 -2 3 -4
3
-1 3 -5
1
-1
Output #1
5
4
2
0
InputCopy OutputCopy
题目信息
题号
1882C
时间限制
2 s
内存限制
256 MB
标签
暴力
贪心

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。