последовательность - 2

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

int main() {

    std::ifstream fin("input.txt");
    std::ofstream fout("output.txt");

    int n;
    fin >> n;
    vector<int> mass;
    int temp;
    for (int i = 0; i < n; i++) {
        fin >> temp;
        mass.push_back(temp);
    }
    mass.push_back(-1000001);

    int left = 0, right = 1, answ = 0;

    for (int i = 1; i < mass.size() - 2; i++) {

        if (mass[i - 1] > mass[left]) {
            left = i - 1;
        }

        if (right <= i) {
            int right_data = -1000001;
            for (int j = i + 1; j < mass.size(); j++) {
                if (right_data <= mass[j] || (mass[j] == -1000001 && right == i)) {
                    right = j;
                    right_data = mass[right];
                }
            }
        }

        if (mass[left] > mass[i] && mass[right] > mass[i]) {
            mass[i] = -1000001;
            answ++;
        }

    }

    fout << n - answ << endl;

    for (int i = 0; i < mass.size(); i++) {
        if (mass[i] != -1000001) {
            fout << mass[i] << " ";
        }
    }

    return 0;
}