AtCoder Regular Contest 158
B
Sum-Product Ratio
AtCoder
⌀ 1446
原题
← AC →
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Problem Statement

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You are given non-zero integers $x_1, \ldots, x_N$. Find the minimum and maximum values of $\dfrac{x_i+x_j+x_k}{x_ix_jx_k}$ for integers $i$, $j$, $k$ such that $1\leq i < j < k\leq N$.

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Constraints

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  • $3\leq N\leq 2\times 10^5$
  • $-10^6\leq x_i \leq 10^6$
  • $x_i\neq 0$
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Input

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The input is given from Standard Input in the following format:

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N
x_1 \ldots x_N

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Output

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Print the minimum value of $\dfrac{x_i+x_j+x_k}{x_ix_jx_k}$ in the first line and the maximum value in the second line.

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Your output will be considered correct when the absolute or relative error is at most $10^{-12}$.

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样例

Input #1
4
-2 -4 4 5
Output #1
-0.175000000000000
-0.025000000000000
$\dfrac{x_i+x_j+x_k}{x_ix_jx_k}$ can take the following four values. - $(i,j,k) = (1,2,3)$: $\dfrac{(-2) + (-4) + 4}{(-2)\cdot (-4)\cdot 4} = -\dfrac{1}{16}$. - $(i,j,k) = (1,2,4)$: $\dfrac{(-2) + (-4) + 5}{(-2)\cdot (-4)\cdot 5} = -\dfrac{1}{40}$. - $(i,j,k) = (1,3,4)$: $\dfrac{(-2) + 4 + 5}{(-2)\cdot 4\cdot 5} = -\dfrac{7}{40}$. - $(i,j,k) = (2,3,4)$: $\dfrac{(-4) + 4 + 5}{(-4)\cdot 4\cdot 5} = -\dfrac{1}{16}$. Among them, the minimum is $-\dfrac{7}{40}$, and the maximum is $-\dfrac{1}{40}$.
Input #2
4
1 1 1 1
Output #2
3.000000000000000
3.000000000000000
Input #3
5
1 2 3 4 5
Output #3
0.200000000000000
1.000000000000000
题目信息
题号
arc158_b
时间限制
2 s
内存限制
1024 MB

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