Codeforces Round 174 (Div. 1)
D
Cows and Cool Sequences
Codeforces
2400
原题
← CE →
翻译中…

Bessie and the cows have recently been playing with "cool" sequences and are trying to construct some. Unfortunately they are bad at arithmetic, so they need your help!

翻译中…

A pair $(*x*, *y*)$ of positive integers is "cool" if $*x*$ can be expressed as the sum of $*y*$ consecutive integers (not necessarily positive). A sequence $(*a*_{1}, *a*_{2}, ..., *a*_{*n*})$ is "cool" if the pairs $(*a*_{1}, *a*_{2}), (*a*_{2}, *a*_{3}), ..., (*a*_{*n* - 1}, *a*_{*n*})$ are all cool.

翻译中…

The cows have a sequence of $*n*$ positive integers, $*a*_{1}, *a*_{2}, ..., *a*_{*n*}$. In one move, they may replace some $*a*_{*i*}$ with any other positive integer (there are no other limits on the new value of $*a*_{*i*}$). Determine the smallest number of moves needed to make the resulting sequence cool.

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Input

翻译中…

The first line contains a single integer, $*n*$ ($2 ≤ *n* ≤ 5000$). The next line contains $*n*$ space-separated integers, $*a*_{1}, *a*_{2}, ..., *a*_{*n*}$ ($1 ≤ *a*_{*i*} ≤ 10^{15}$).

翻译中…

Please do not use the %lld specifier to read or write 64-bit integers in С++. It is preferred to use the cin, cout streams or the %I64d specifier.

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Output

翻译中…

A single integer, the minimum number of $*a*_{*i*}$ that must be changed to make the sequence cool.

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Note

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In the first sample, the sequence is already cool, so we don't need to change any elements. In the second sample, we can change $*a*_{2}$ to 5 and $*a*_{3}$ to 10 to make (20, 5, 10, 4) which is cool. This changes 2 elements.

翻译中…

样例

Input #1
3
6 4 1
Output #1
0
InputCopy OutputCopy
Input #2
4
20 6 3 4
Output #2
2
InputCopy OutputCopy
题目信息
题号
283D
时间限制
2 s
内存限制
256 MB
标签
动态规划
数学
数论

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。