Monikulmio

input/code.cpp: In function 'int main(int, char**)':
input/code.cpp:143:13: warning: 'prevY' may be used uninitialized in this function [-Wmaybe-uninitialized]
  143 |     drawLine(prevX, prevY, firstX, firstY, grid);
      |     ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
input/code.cpp:143:13: warning: 'prevX' may be used uninitialized in this function [-Wmaybe-uninitialized]
input/code.cpp:143:13: warning: 'firstY' may be used uninitialized in this function [-Wmaybe-uninitialized]
input/code.cpp:143:13: warning: 'firstX' may be used uninitialized in this function [-Wmaybe-uninitialized]

#include <algorithm>
#include <cstdlib>
#include <iostream>
#include <stdexcept>
#include <string>

// #define DEBUG

class Grid {
    char *data;
#ifdef DEBUG
    int size;
#endif // DEBUG
public:
    const int width;
    const int height;

    Grid(int width, int height) : data(new char[width * height])
#ifdef DEBUG
    , size(width * height)
#endif // DEBUG
    , width(width), height(height)
    {
        for (int i = 0; i < width * height; i++) {
            data[i] = '#';
        }
    }

    inline int getIndex(int x, int y) {
        return (y - 1) * width + x - 1;
    }

    inline bool inside(int x, int y) {
        return x >= 1 && x <= width && y >= 1 && y <= height;
    }

    char get(int x, int y) {
        const int i = getIndex(x, y);
#ifdef DEBUG
        if (i >= size) throw std::runtime_error("index: " + std::to_string(i) + ", size: " + std::to_string(size));
        if (x > width) throw std::runtime_error("x: " + std::to_string(x) + ", width: " + std::to_string(width));
        if (y > height) throw std::runtime_error("y: " + std::to_string(y) + ", height: " + std::to_string(height));
#endif // DEBUG
        
        return data[i];
    }

    void set(int x, int y, char value) {
        const int i = getIndex(x, y);
#ifdef DEBUG
        if (i >= size) throw std::runtime_error("index: " + std::to_string(i) + ", size: " + std::to_string(size));
        if (x > width) throw std::runtime_error("x: " + std::to_string(x) + ", width: " + std::to_string(width));
        if (y > height) throw std::runtime_error("y: " + std::to_string(y) + ", height: " + std::to_string(height));
#endif // DEBUG
        
        data[i] = value;
    }

    void print() {
        for (int y = 1; y <= height; y++) {
            for (int x = 1; x <= width; x++) {
                std::cout << get(x, y);
            }

            std::cout << std::endl;
        }
    }
};

char getDirection(int dx, int dy) {
    if (dx == 0) return '|';
    if (dy == 0) return '=';
    if (dy < 0) {
        if (dx < 0) return '\\';
        else return '/';
    } else {
        if (dx < 0) return '/';
        else return '\\';
    }
}

void drawLine(int prevX, int prevY, int x, int y, Grid& grid) {
    int dx = x - prevX;
    int dy = y - prevY;
    int steps = std::max(std::abs(dx), std::abs(dy));

    char direction = getDirection(dx, dy);

    for (int step = 0; step < steps - 1; step++) {
        if (dx != 0) dx -= dx / std::abs(dx);
        if (dy != 0) dy -= dy / std::abs(dy);

        grid.set(prevX + dx, prevY + dy, direction);
    }
}

void paint(Grid& grid, int x, int y) {
    if (!grid.inside(x, y) || grid.get(x, y) != '#') return;

    grid.set(x, y, '.');

    paint(grid, x - 1, y);
    paint(grid, x + 1, y);
    paint(grid, x, y - 1);
    paint(grid, x, y + 1);
}

void paintBackground(Grid& grid) {
    for (int x = 1; x <= grid.width; x++) {
        paint(grid, x, 1);
        paint(grid, x, grid.height);
    }

    for (int y = 2; y <= grid.height; y++) {
        paint(grid, 1, y);
        paint(grid, grid.width, y);
    }
}

int main([[maybe_unused]] int argc, [[maybe_unused]] char *argv[]) {
    int height, width, lines; std::cin >> height >> width >> lines;

    Grid grid(width, height);
    
    bool first = true;
    int firstX, firstY, prevX, prevY, x, y;
    for (int i = 0; i < lines; i++) {
        std::cin >> y >> x;

        grid.set(x, y, '*');

        if (!first) drawLine(prevX, prevY, x, y, grid);
        else {
            firstX = x;
            firstY = y;
            first = false;
        }

        prevX = x;
        prevY = y;
    }

    drawLine(prevX, prevY, firstX, firstY, grid);
    paintBackground(grid);

    grid.print();
}

Test 1 (public)

Verdict: ACCEPTED

Test 2 (public)

Verdict: ACCEPTED

Test 3 (public)

Verdict: ACCEPTED

Test 4 (public)

Verdict: ACCEPTED

Test 5 (public)

Verdict: ACCEPTED

Test 6 (public)

Verdict: ACCEPTED

Test 7 (public)

Verdict: ACCEPTED

Test 8 (public)

Verdict: ACCEPTED

Test 9 (public)

Verdict: ACCEPTED

Test 10 (public)

Verdict: ACCEPTED