题意:有一长度为\(n\)的序列,求其中任意五个元素乘积的最大值.

题解:先排序,然后乘积能是正数就搞正数,模拟一下就好了.

代码:

int t;
ll n;
ll a[N];

int main() {
    ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    cin>>t;
    while(t--){
        cin>>n;
        for(int i=1;i<=n;++i){
            cin>>a[i];
        }
        sort(a+1,a+1+n);
        ll cnt1=a[n]*a[n-1]*a[n-2]*a[n-3]*a[n-4];
        ll cnt2=a[1]*a[2]*a[3]*a[4]*a[5];
        ll cnt3=a[n]*a[1]*a[2]*a[3]*a[4];
        ll cnt4=a[1]*a[2]*a[n]*a[n-1]*a[n-2];
        ll res=max(cnt1,max(cnt2,max(cnt3,cnt4)));
        cout<<res<<endl;
    }
return 0;
}