题解 | 【模板】序列操作

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

int main() {
    int n, code, i, x;
    cin >> n;
    vector<int> v;
    while (n--) {
        cin >> code;
        if (code == 1) {
            cin >> x;
            v.push_back(x);
        } else if (code == 2) {
            v.pop_back();
        } else if (code == 3) {
            cin >> i;
            cout << v[i] << endl;
        } else if (code == 4) {
            cin >> i >> x;
            v.push_back(0);
            int j = v.size();
            for (; j > i + 1; --j) {
                v[j] = v[j - 1];
            }
            v[j] = x;
        } else if (code == 5) {
            sort(v.begin(), v.end());
        } else if (code == 6) {
            sort(v.begin(), v.end(), greater<int>());
        } else if (code == 7) {
            cout << v.size() << endl;
        } else if (code == 8) {
            for (const auto& e : v) {
                cout << e << " ";
            }
            cout << endl;
        }
    }
}
// 64 位输出请用 printf("%lld")