一开始看错题目,以为是可以排列的。
1.#include<algorithm>
#include <iterator>
#include<cstdio>
#include<set>
#include<cstring>
#include<string>
#include<map>
#include<vector>
#include<math.h>
#include<stack>
#include<iostream>
#include<sstream>
#include<queue>
#include<cassert>
const int maxn=6000;
using namespace std;
deque<int>q,acle[8];
int a[25];
int main()
{//freopen("input.txt","r",stdin);
int mycount=0;
int n;
int k=0;
while(cin>>n)
{int count=0;
long long finalsum=0;
mycount++;
for(int i=0;i<n;i++)
{
cin>>a[i];
}
if(k!=0)
{
cout<<"\n";
}
sort(a,a+n);
int negative_count=0;
int tranform_positvevalues=-1;
int tranform_negativevalues=-1;
int acount=0;
for(int i=0;i<n;i++)
{
if(i+1<n)
{if(a[i]*a[i+1]<=0&&acount==0)
{acount=1;
tranform_negativevalues=i;}
}
if(a[i]<0)
{
negative_count++;
}
if(a[i]>0)
{
break;
}
if(i+1<n)
{
if(a[i]*a[i+1]>=0&&a[i]>=0&&a[i+1]>=0)
tranform_positvevalues=i;
}
}
long long sum=1;
long long sum1=1;
if(tranform_positvevalues!=-1)
{int pd=0;
for(int i=tranform_positvevalues+1;i<n;i++)
{pd=1;
sum=sum*a[i];
}
if(finalsum<sum&&pd==1)
{
finalsum=sum;
}
}
if(tranform_negativevalues!=-1)
{ int pd=0;
sum=1;
sum1=1;
if(tranform_negativevalues%2==0)
{
for(int i=1;i<tranform_negativevalues+1;i++)
{ pd=1;
sum=sum*a[i];
}
}
else if(tranform_negativevalues%2==1)
{
for(int i=0;i<tranform_negativevalues+1;i++)
{ pd=1;
sum=sum*a[i];
}
}
if(tranform_positvevalues==-1)
{
for(int i=tranform_negativevalues+1;i<n;i++)
{pd=1;
sum1=sum1*a[i];
sum=sum*a[i];
}
if(sum<sum1)
{
sum=sum1;
}
}
if(finalsum<sum&&pd==1)
{
finalsum=sum;
}
}
if(tranform_positvevalues==-1&&tranform_negativevalues==-1)
{sum=1;
if(negative_count==0)
{
for(int i=0;i<n;i++)
{
sum=sum*a[i];
}
if(finalsum<sum1)
{
finalsum=sum;
}
}
else
{
if(n%2==0)
{
finalsum=0;
}
else
{int pd=0;
for(int i=0;i<n;i++)
{pd=1;
sum=sum*a[i];
}
if(finalsum<sum&&pd==1)
{
finalsum=sum;
}
}
}
}
if(n==0)
finalsum=0;
cout<<"Case #"<<mycount<<": The maximum product is "<<finalsum<<"."<<"\n";
k++;
}
}