题解 | 【模板】序列操作

#include <iostream>
#include<algorithm>
#include<vector>
using namespace std;

int main() {
    int q;
    cin>>q;
    vector<int> vec;
    while(q--){
        int op;
        cin>>op;
        switch(op){
            case 1:
            int x;
            cin>>x;
            vec.push_back(x);
            break;
            case 2:
            vec.pop_back();
            break;
            case 3:
            int i;
            cin>>i;
            cout<<vec.at(i)<<'\n';
            break;
            case 4:
            cin>>i>>x;
            vec.insert(vec.begin()+i+1,x);
            break;
            case 5:
            sort(vec.begin(),vec.end());
            break;
            case 6:
            sort(vec.begin(),vec.end(),greater<int>());
            break;
            case 7:
            cout<<vec.size();
            cout<<'\n';
            break;
            case 8:
            for(int num:vec)
            cout<<num<<" ";
            cout<<'\n';
            break;
        }
    }
}
// 64 位输出请用 printf("%lld")