Difference between revisions of "2020 CCPC Online Contest"

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== Problem C ==
 
== Problem C ==
 
Solved by bingoier. 00:27:30
 
Solved by bingoier. 00:27:30
 +
 +
贪心选择最后一个信封柜即可
  
 
== Problem D ==
 
== Problem D ==
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== Problem E ==
 
== Problem E ==
 
Solved by yanghong. 00:36:01(+2)
 
Solved by yanghong. 00:36:01(+2)
 +
 +
结论为 $sg(x) = [c_2] + \sum_{i > 2} c_i$
 +
 +
其中 $x = 2^{c_2} 3 ^ {c_3} 5 ^ {c_5} \dots $
  
 
== Problem F ==
 
== Problem F ==
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== Problem K ==
 
== Problem K ==
Solved by Once. 00:45:19(-1)
+
Solved by Once. 00:45:19(+1)
  
 
大胆猜测,当且仅当只有左上角非零时答案为原矩阵,感觉证明也挺简单的。
 
大胆猜测,当且仅当只有左上角非零时答案为原矩阵,感觉证明也挺简单的。
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== Problem M ==
 
== Problem M ==
 +
Unsolved.

Latest revision as of 14:32, 7 October 2020

Problem A

Unsolved.

Problem B

Solved by all. 02:24:09(+1)

每个节点向其某个质因子连边,之后所有素数向 $2$ 连边。答案即为区间自然数和加上区间素数和,用 min25 筛出即可。

Problem C

Solved by bingoier. 00:27:30

贪心选择最后一个信封柜即可

Problem D

Unsolved.

Problem E

Solved by yanghong. 00:36:01(+2)

结论为 $sg(x) = [c_2] + \sum_{i > 2} c_i$

其中 $x = 2^{c_2} 3 ^ {c_3} 5 ^ {c_5} \dots $

Problem F

Solved by Once. 04:43:11(+4)

把所有边界点带入后方的连续函数验证连续性即可。

取消同步要人命。

Problem G

Solved by Once. 00:16:43

大胆猜测答案就是出现最多的字母的出现次数。

Problem H

Unsolved.

Problem I

Unsolved.

Problem J

Solved by Once. 00:08:01

检查是否有相邻的 $1$ 即可。

Problem K

Solved by Once. 00:45:19(+1)

大胆猜测,当且仅当只有左上角非零时答案为原矩阵,感觉证明也挺简单的。

Problem L

Unsolved.

Problem M

Unsolved.