题解 | 牛牛与切割机

 #include<bits/stdc++.h>
 using namespace std;
 #define int long long
 const int N=1e6+10;
 int a[N],sum[N];
 signed main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>a[i];
    }
    for(int i=1;i<=n;i++){
        sum[i]=sum[i-1]+a[i];
    }
    int sum1=0,sum2=0;
    int total=1e18;
    int current=0;
    for(int i=1;i<n;i++){//一定要i<n，不然sum2=0;使得最小为0
        sum1=sum[i];
        sum2=sum[n]-sum[i];
        current=sum1*sum2;
        if(current<total)total=current;
    }
    cout<<total;

 }