题解 | 【模板】序列操作

#include <algorithm>
#include<bits/stdc++.h>
#include <functional>
#include <iostream>
#include <vector>
using namespace std;
int q,a,b,c;vector<int>v;
int main(){
    cin>>q;
    for (int i=0; i<q;i++) {
    cin>>a;
    if (a==1) {
        cin>>b;v.push_back(b);
    }else if (a==2) {
        v.pop_back();
    }else if (a==3) {
        cin>>b;cout<<v[b]<<endl;
    }else if (a==4) {
    cin>>b>>c;
    for (int j=b+1; j<v.size();++j) {
    int temp=v[j];v[j]=c;c=temp;
    }
    v.push_back(c);
    }else if (a==5) {
    sort(v.begin(),v.end());
    }else if (a==6) {
    sort(v.begin(),v.end(),greater<int>());
    }else if (a==7) {
    cout<<v.size()<<endl;
    }else {
    for (int j=0; j<v.size();j++) {
        if (j==(v.size()-1)) {
        cout<<v[j]<<endl;break;
        }
    cout<<v[j]<<' ';
    }
    }
    }
    return 0;
}