Codeforces Round 614 (Div. 2)
D
Aroma's Search
Codeforces
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原题
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With a new body, our idol Aroma White (or should we call her Kaori Minamiya?) begins to uncover her lost past through the OS space.

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The space can be considered a 2D plane, with an infinite number of data nodes, indexed from $0$, with their coordinates defined as follows:

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  • The coordinates of the $0$-th node is $(x_0, y_0)$
  • For $i \gt 0$, the coordinates of $i$-th node is $(a_x \cdot x_{i-1} + b_x, a_y \cdot y_{i-1} + b_y)$
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Initially Aroma stands at the point $(x_s, y_s)$. She can stay in OS space for at most $t$ seconds, because after this time she has to warp back to the real world. She doesn't need to return to the entry point $(x_s, y_s)$ to warp home.

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While within the OS space, Aroma can do the following actions:

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  • From the point $(x, y)$, Aroma can move to one of the following points: $(x-1, y)$, $(x+1, y)$, $(x, y-1)$ or $(x, y+1)$. This action requires $1$ second.
  • If there is a data node at where Aroma is staying, she can collect it. We can assume this action costs $0$ seconds. Of course, each data node can be collected at most once.
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Aroma wants to collect as many data as possible before warping back. Can you help her in calculating the maximum number of data nodes she could collect within $t$ seconds?

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Input

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The first line contains integers $x_0$, $y_0$, $a_x$, $a_y$, $b_x$, $b_y$ ($1 \leq x_0, y_0 \leq 10^{16}$, $2 \leq a_x, a_y \leq 100$, $0 \leq b_x, b_y \leq 10^{16}$), which define the coordinates of the data nodes.

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The second line contains integers $x_s$, $y_s$, $t$ ($1 \leq x_s, y_s, t \leq 10^{16}$) – the initial Aroma's coordinates and the amount of time available.

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Output

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Print a single integer — the maximum number of data nodes Aroma can collect within $t$ seconds.

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Note

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In all three examples, the coordinates of the first $5$ data nodes are $(1, 1)$, $(3, 3)$, $(7, 9)$, $(15, 27)$ and $(31, 81)$ (remember that nodes are numbered from $0$).

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In the first example, the optimal route to collect $3$ nodes is as follows:

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  • Go to the coordinates $(3, 3)$ and collect the $1$-st node. This takes $|3 - 2| + |3 - 4| = 2$ seconds.
  • Go to the coordinates $(1, 1)$ and collect the $0$-th node. This takes $|1 - 3| + |1 - 3| = 4$ seconds.
  • Go to the coordinates $(7, 9)$ and collect the $2$-nd node. This takes $|7 - 1| + |9 - 1| = 14$ seconds.
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In the second example, the optimal route to collect $2$ nodes is as follows:

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  • Collect the $3$-rd node. This requires no seconds.
  • Go to the coordinates $(7, 9)$ and collect the $2$-th node. This takes $|15 - 7| + |27 - 9| = 26$ seconds.
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In the third example, Aroma can't collect any nodes. She should have taken proper rest instead of rushing into the OS space like that.

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样例

Input #1
1 1 2 3 1 0
2 4 20
Output #1
3
InputCopy OutputCopy
Input #2
1 1 2 3 1 0
15 27 26
Output #2
2
InputCopy OutputCopy
Input #3
1 1 2 3 1 0
2 2 1
Output #3
0
InputCopy OutputCopy
题目信息
题号
1293D
时间限制
1 s
内存限制
256 MB

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。