2016暑假多校联合---GCD
Problem Description
Give you a sequence of ).
Input
The first line of input contains a number i, stand for the i-th queries.
Output
For each case, you need to output “Case #:t” at the beginning.(with quotes, ).
Sample Input
1
5
1 2 4 6 7
4
1 5
2 4
3 4
4 4
Sample Output
Case #1:
1 8
2 4
2 4
6 1
思路:我们注意观察gcd(al,al+1,...,ar),当l固定不动的时候,r=l...nr=l...n时,我们可以容易的发现,随着rr的増大,gcd(al,al+1,...,ar)是递减的,同时gcd(al,al+1,...,ar)最多 有log 1000,000,000个不同的值,为什么呢?因为al最多也就有log 1000,000,00