PW All

#include <string>
#include <fstream>
#include <sstream>
#include <iostream>
#include <unordered_set>
#include <deque>

using namespace std;

// class Entity {
// public:

//     Entity(int x, int y, vector<string>& board) : x(x), y(y), board(board) {}
//     // Part 2
//     Entity(int x, int y, int idx, vector<string>& board) : x(x), y(y), idx(idx), board(board) {}

//     char get() {
//         int m = board.size();
//         int n = board[0].size();
//         int tx = x;
//         int ty = m-1-y;

//         // check boundary
//         if (tx < 0 || ty < 0 || tx >= n || ty >= m) {
//             throw runtime_error("out of boundary");
//         }

//         return board[ty][tx];
//     }

//     void debug() {
//         cout << "x: " << x << " y: " << y << " idx: " << idx << endl;
//         for (int i = 0; i < board.size(); i++) {
//             cout << board[i] << endl;
//         }
//     }

//     int x = 0;
//     int y = 0;
//     vector<string> board;

//     // Part 2
//     int idx;
// };

class Entity {
public:
    int x;
    int y;
    int idx;

    Entity(int x, int y, int idx) : x(x), y(y), idx(idx) {}

    void add(string str) {
        if (x >= str.size()) {
            throw runtime_error("x out of bounds");
        }

        dq.push_back(str[x]);
        if (dq.size() > y + 1) {
            dq.pop_front();
        }
    }

    char get() {
        if (dq.size() != y + 1) {
            throw runtime_error("y out of bounds");
        }

        return dq.front();
    }

    deque<char> dq;
};

class Parser {
public:
    Parser(string filename) : filename(filename) {}

    Entity parse() {
        ifstream file(filename);
        if (!file.is_open()) {
            throw runtime_error("cannot open file");
        }

        vector<string> res;
        string line;
        getline(file, line);

        // Parse x, y
        char delim;
        int x, y;
        istringstream iss(line);
        iss >> delim >> x >> delim >> y >> delim;

        Entity e = Entity(x, y, -1);

        while (getline(file, line)) {
            // res.push_back(line);
            e.add(line);
        }

        file.close();
        // return 
        return e;
    }

    // Part 2
    Entity parseUtil(ifstream& file) {
        vector<string> res;
        string line;

        // Parse index
        getline(file, line);
        int idx;
        istringstream iss_idx(line);
        iss_idx >> idx;

        // Part 3
        if (seen.count(idx)) {
            vector<string> res;
            // return Entity(-1, -1, -1, res);
            return Entity(-1, -1, -1);
        }
        seen.insert(idx);

        // Parse x, y
        getline(file, line);
        char delim;
        int x, y;
        istringstream iss(line);
        iss >> delim >> x >> delim >> y >> delim;

        Entity e = Entity(x, y, idx);

        // Parse board portion, if digit means it's next chunk of entity.
        while (!isdigit(file.peek()) && getline(file, line) && !line.empty()) {
            // res.push_back(line);
            e.add(line);
        }

        // return Entity(x, y, idx, res);
        return e;
    }

    vector<Entity> parseList() {
        ifstream file(filename);
        if (!file.is_open()) {
            throw runtime_error("cannot open file");
        }

        vector<Entity> res;
        while (file.peek() != EOF && file.peek() != '\n') {
            Entity e = parseUtil(file);
            if (e.x == -1) break;
            res.push_back(e);
        }

        return res;
    }

    string filename;

    // Part 3
    unordered_set<int> seen;
};

string getPW() {
    Parser parser = Parser("company-tags/instacart/part2_test1.txt");
    vector<Entity> entityList = parser.parseList();

    string res = string(entityList.size(), ' ');
    for (Entity e: entityList) {
        char c = e.get();
        res[e.idx] = c;
    }

    return res;
}

char part1() {
    Parser parser = Parser("company-tags/instacart/test1.txt");
    Entity e = parser.parse();
    return e.get();
}

string getPW_Part3() {
    Parser parser = Parser("company-tags/instacart/part3_test1.txt");
    vector<Entity> entityList = parser.parseList();

    string res = string(entityList.size(), ' ');
    for (Entity e : entityList) {
        // e.debug();
        char c = e.get();
        res[e.idx] = c;
    }

    return res;
}

int main() {
    cout << part1() << endl;
    cout << getPW() << endl;
    // cout << getPW_Part3() << endl;
    return 0;
}```