#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    cout << "Advent of Code 2021 - Day 3 Part 2" << endl;

    vector<vector<char>> inputBits;

    ifstream filein("input");
    for(string line; getline(filein, line);) {
        vector<char> bits;
        for(int i = 0; i < 12; i++) {
            if (line[i] == '1') {
                bits.push_back(1);
            }
            else {
                bits.push_back(0);
            }
        }
        inputBits.push_back(bits);
    }

    vector<vector<char>> oxygen = inputBits;

    int x, greater = 0;
    while (oxygen.size() != 1) {
        for(int i = 0; i < oxygen.size(); i++) {
            if(oxygen[i][x] == 1) {
                greater++;
            }
        }

        char matcher;
        if(greater > (oxygen.size() / 2)) {
            matcher = 1;
            } else {
            matcher = 0;
        }

        oxygen.erase(
            remove_if(
                oxygen.begin(),
                oxygen.end(),
                [x, matcher](vector<char> z) {
                    if (z[x] != matcher) {
                        return true;
                    }
                    return false;
                }
            ), oxygen.end()
        );

        x++;
        greater = 0;
    }

    vector<vector<char>> co2 = inputBits;

    x = 0;
    greater = 0;

    while (co2.size() != 1) {
        for(int i = 0; i < co2.size(); i++) {
            if(co2[i][x] == 0) {
                greater++;
            }
        }

        char matcher;
        if(greater > (co2.size() / 2)) {
            matcher = 0;
            } else {
            matcher = 1;
        }

        co2.erase(
            remove_if(
                co2.begin(),
                co2.end(),
                [x, matcher](vector<char> z) {
                    if (z[x] != matcher) {
                        return true;
                    }
                    return false;
                }
            ), co2.end()
        );

        x++;
        greater = 0;
    }

    for (auto c : oxygen) {
        for (auto z : c) {
            cout << +z;
        }
    }
    cout << endl;

    for (auto c : co2) {
        for (auto z : c) {
            cout << +z;
        }
    }
    cout << endl;

    unsigned int oxygen_final = 0;
    unsigned int co2_final = 0;

    for(int x = 0; x < 12; x++) {
        if(oxygen[0][x] == 1) {
            oxygen_final |= 1UL << 11 - x;
        }
        if(co2[0][x] == 1) {
            co2_final |= 1UL << 11 - x;
        }
    }

    cout << oxygen_final << endl << co2_final << endl;
    cout << oxygen_final * co2_final << endl;

    return 0;
}