Maximun product

 

Given a sequence of integers S = {S₁, S₂, ..., S_n}, you shoulddetermine what is the value of the maximum positive product involving consecutive terms of S. Ifyou cannot find a positive sequence, you should consider 0 as the value of the maximum product.

 

Each test case starts with 1 ≤ N ≤ 18, the number of elements in a sequence. Each elementS_i is an integer such that -10 ≤ S_i ≤ 10. Next line will haveN integers, representing the value of each element in the sequence. There is a blank line aftereach test case. The input is terminated by end of file (EOF).

 

For each test case you must print the message: Case #M: The maximum product is P., where M isthe number of the test case, starting from 1, and P is the value of the maximum product. Aftereach test case you must print a blank line.

 

3
2 4 -3

5
2 5 -1 2 -1

Case #1: The maximum product is 8.

Case #2: The maximum product is 20.


枚举每一个长度组合，不断更新最大值，不过要注意有可能18个数都是10，那么最大值是多少？int还存得下吗？

#include"iostream"
#include"cstring"
using namespace std;
int main()
{
 long long ans=-99999999;
 int ch,f;
 long long an=1;
 int a[20];
 f=1;
 int n;
 while(cin>>n)
 {
    for(int i=0;i<n;i++)
    {
        cin>>ch;
        a[i]=ch;
        an*=ch;
        if(an>ans)
        {
         ans=an;
        }
    }
    for(int j=n-1;j>=0;j--)
    {
        an=1;
        for(int k=j;k>=0;k--)
        {
        an*=a[k];
        if(an>ans)
        {
         ans=an;
        }
        }
    }
    if(ans<0) ans=0;
    cout<<"Case #"<<f++<<": The maximum product is "<<ans<<'.'<<endl;
    cout<<endl;
    ans=-99999999;
    an=1;
 }


    return 0;
}