Codeforces Round 410 (Div. 2)
C
Mike and gcd problem
Codeforces
1700
原题
← BD →
翻译中…

Mike has a sequence $*A* = [*a*_{1}, *a*_{2}, ..., *a*_{*n*}]$ of length $*n*$. He considers the sequence $*B* = [*b*_{1}, *b*_{2}, ..., *b*_{*n*}]$ beautiful if the $*gcd*$ of all its elements is bigger than $1$, i.e. image.

翻译中…

Mike wants to change his sequence in order to make it beautiful. In one move he can choose an index $*i*$ ($1 ≤ *i* < *n*$), delete numbers $*a*_{*i*}, *a*_{*i* + 1}$ and put numbers $*a*_{*i*} - *a*_{*i* + 1}, *a*_{*i*} + *a*_{*i* + 1}$ in their place instead, in this order. He wants perform as few operations as possible. Find the minimal number of operations to make sequence $*A*$ beautiful if it's possible, or tell him that it is impossible to do so.

翻译中…

image is the biggest non-negative number $*d*$ such that $*d*$ divides $*b*_{*i*}$ for every $*i*$ ($1 ≤ *i* ≤ *n*$).

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Input

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The first line contains a single integer $*n*$ ($2 ≤ *n* ≤ 100 000$) — length of sequence $*A*$.

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The second line contains $*n*$ space-separated integers $*a*_{1}, *a*_{2}, ..., *a*_{*n*}$ ($1 ≤ *a*_{*i*} ≤ 10^{9}$) — elements of sequence $*A*$.

翻译中…

Output

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Output on the first line "YES" (without quotes) if it is possible to make sequence $*A*$ beautiful by performing operations described above, and "NO" (without quotes) otherwise.

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If the answer was "YES", output the minimal number of moves needed to make sequence $*A*$ beautiful.

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Note

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In the first example you can simply make one move to obtain sequence $[0, 2]$ with image.

翻译中…

In the second example the $*gcd*$ of the sequence is already greater than $1$.

翻译中…

样例

Input #1
2
1 1
Output #1
YES
1
InputCopy OutputCopy
Input #2
3
6 2 4
Output #2
YES
0
InputCopy OutputCopy
Input #3
2
1 3
Output #3
YES
1
InputCopy OutputCopy
题目信息
题号
798C
时间限制
2 s
内存限制
256 MB
标签
动态规划
贪心
数论

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