VK Cup 2016 - Round 1 (Div. 2 Edition)
D
Bear and Polynomials
Codeforces
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原题
← CE →
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Limak is a little polar bear. He doesn't have many toys and thus he often plays with polynomials.

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He considers a polynomial valid if its degree is $*n*$ and its coefficients are integers not exceeding $*k*$ by the absolute value. More formally:

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Let $*a*_{0}, *a*_{1}, ..., *a*_{*n*}$ denote the coefficients, so image. Then, a polynomial $*P*(*x*)$ is valid if all the following conditions are satisfied:

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  • $*a*_{*i*}$ is integer for every $*i*$;
  • $|*a*_{*i*}| ≤ *k*$ for every $*i*$;
  • $*a*_{*n*} ≠ 0$.
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Limak has recently got a valid polynomial $*P*$ with coefficients $*a*_{0}, *a*_{1}, *a*_{2}, ..., *a*_{*n*}$. He noticed that $*P*(2) ≠ 0$ and he wants to change it. He is going to change one coefficient to get a valid polynomial $*Q*$ of degree $*n*$ that $*Q*(2) = 0$. Count the number of ways to do so. You should count two ways as a distinct if coefficients of target polynoms differ.

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Input

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The first line contains two integers $*n*$ and $*k*$ ($1 ≤ *n* ≤ 200 000, 1 ≤ *k* ≤ 10^{9}$) — the degree of the polynomial and the limit for absolute values of coefficients.

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The second line contains $*n* + 1$ integers $*a*_{0}, *a*_{1}, ..., *a*_{*n*}$ ($|*a*_{*i*}| ≤ *k*, *a*_{*n*} ≠ 0$) — describing a valid polynomial image. It's guaranteed that $*P*(2) ≠ 0$.

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Output

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Print the number of ways to change one coefficient to get a valid polynomial $*Q*$ that $*Q*(2) = 0$.

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Note

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In the first sample, we are given a polynomial $*P*(*x*) = 10 - 9*x* - 3*x*^{2} + 5*x*^{3}$.

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Limak can change one coefficient in three ways:

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  1. He can set $*a*_{0} = - 10$. Then he would get $*Q*(*x*) = - 10 - 9*x* - 3*x*^{2} + 5*x*^{3}$ and indeed $*Q*(2) = - 10 - 18 - 12 + 40 = 0$.
  2. Or he can set $*a*_{2} = - 8$. Then $*Q*(*x*) = 10 - 9*x* - 8*x*^{2} + 5*x*^{3}$ and indeed $*Q*(2) = 10 - 18 - 32 + 40 = 0$.
  3. Or he can set $*a*_{1} = - 19$. Then $*Q*(*x*) = 10 - 19*x* - 3*x*^{2} + 5*x*^{3}$ and indeed $*Q*(2) = 10 - 38 - 12 + 40 = 0$.
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In the second sample, we are given the same polynomial. This time though, $*k*$ is equal to $12$ instead of $10^{9}$. Two first of ways listed above are still valid but in the third way we would get $|*a*_{1}| > *k*$ what is not allowed. Thus, the answer is $2$ this time.

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样例

Input #1
3 1000000000
10 -9 -3 5
Output #1
3
InputCopy OutputCopy
Input #2
3 12
10 -9 -3 5
Output #2
2
InputCopy OutputCopy
Input #3
2 20
14 -7 19
Output #3
0
InputCopy OutputCopy
题目信息
题号
658D
时间限制
2 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。