#include<bits/stdc++.h>
using namespace std;
int n,a[100005],b[100005],f[100005],qzh[100005];
int main(){
    int t;
    cin>>t;
    b[0]=1;
    while(t--){
        cin>>n;
        int cute=1145141919;
        vector<int>v;
        vector<int>w;
        int k=0;
        for(int i=1;i<=n;i++){
            cin>>a[i];
            qzh[i]=qzh[i-1]+a[i];
            if(i+a[i]>n&&i<n){b[i]=b[i-1]-1;
                if(i+a[i]-n<=cute)cute=i+a[i]-n,v.push_back(i),f[i]=-1;
                else f[i]=a[i],a[i]=0;
            }else if(a[i]<b[i-1])f[i]=a[i],b[i]=b[i-1]-1,a[i]=0;
            else b[i]=a[i];
        }
        int f_f=1,ans=0,maxx[100005]={};
        maxx[0]=a[1];
        for(int i=1;i<=min(f_f,n);i++){
            int cat=-114514;
            for(int j=i;j<=min(n,f_f);j++){
            maxx[j]=maxx[j-1];
                if(!f[j]){
                    cat=j;
                    maxx[j]=max(maxx[j],ans-a[cat]+qzh[min(n,f_f+a[cat])]);
                }
                if(k<v.size()&&j==v[k]){
                    w.push_back(i-1);
                    k++;
                }
            }
            if(cat==-114514)break;
            ans-=a[cat];
            f_f=cat+a[cat];
            i=cat;
            //cout<<f_f<<' '<<ans<<' '<<maxx[i]<<endl;
        }
        /*
        cout<<"a ";
        for(int i=1;i<=n;i++)cout<<a[i]<<' ';
        cout<<endl;
        cout<<"b ";
        for(int i=1;i<=n;i++)cout<<b[i]<<' ';
        cout<<endl;
        cout<<"f ";
        for(int i=1;i<=n;i++)cout<<f[i]<<' ';
        cout<<endl;
        cout<<"qzh ";
        for(int i=1;i<=n;i++)cout<<qzh[i]<<' ';
        cout<<endl;
        cout<<"maxx ";
        for(int i=1;i<=n;i++)cout<<maxx[i]<<' ';
        cout<<endl;
        cout<<"v ";
        for(int i=0;i<v.size();i++)cout<<v[i]<<' ';
        cout<<endl;
        cout<<"w ";
        for(int i=0;i<w.size();i++)cout<<w[i]<<' ';
        cout<<endl;
        */
        int nsdd=maxx[min(n,f_f)];
        for(int i=0;i<v.size();i++){
            if(f_f<v[i])break;
            nsdd=max(nsdd,maxx[v[i]]+qzh[n]-qzh[w[i]+a[w[i]]]-a[v[i]]);
        }
        cout<<nsdd<<endl;
    }
    return 0;
}

思路：覆盖过去后被盖住的点就不考虑，对于整到 $n$ 上有造成损耗的点拎出来特判，重新算贡献

咋挂掉了qwq