题解 | 【模板】序列操作

#include <bits/stdc++.h>
#define il inline

using namespace std;
using ll = long long;
using ull = unsigned long long;
using int128=__int128_t;

const ll N = 1e6 + 5, mod = 998244353, inf = LLONG_MAX;
const double esp=1e-3;
double PI=3.1415926;

il void solve(){
    int q;
    cin>>q;
    vector<ll>a;
    while(q--){
        int op;
        cin>>op;
        if(op==1){
            ll x;
            cin>>x;
            a.push_back(x);
        }else if(op==2){
            a.pop_back();
        }else if(op==3){
            ll i;
            cin>>i;
            cout<<a[i]<<'\n';
        }else if(op==4){
            ll i,x;
            cin>>i>>x;
            a.insert(a.begin()+i+1,x);
        }else if(op==5){
            sort(a.begin(),a.end());
        }else if(op==6){
            sort(a.rbegin(),a.rend());
        }else if(op==7){
            cout<<a.size()<<'\n';
        }else{
            for(auto v:a)cout<<v<<" ";
            cout<<'\n';
        }
    }
}

int main() {
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    
    int t = 1;

    //cin >> t;

    while (t--) {
    
        solve();

    }

    return 0;
}