Monikulmio

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
 
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    
    ll n, m, k;
    cin >> n >> m >> k;
    
    vector<vector<char>> grid(n, vector<char>(m, '.'));
    vector<pair<int, int>> corners(k);
    
    
    for (ll i = 0; i < k; i++) {
        cin >> corners[i].first >> corners[i].second;
        grid[corners[i].first - 1][corners[i].second - 1] = '*';
    }
    
    
    
    for (ll i = 0; i < k; i++) {
        ll y1 = corners[i].first -1;
        ll x1 = corners[i].second -1;
        ll y2 = corners[(i+1) % k].first -1;
        ll x2 = corners[(i+1) % k].second -1;
        
        if (x2 == x1) {
            for (ll i = min(y1, y2)+1; i < max(y1, y2); i++) {
                    grid[i][x2] = '|';
            }
        }
        
        else if (y2 == y1) {
            for (ll j = min(x1, x2)+1; j < max(x1, x2); j++) {
                grid[y2][j] = '=';
            }
        }
        
        else {
            ll ystep = -1, xstep = -1;
            if (y2 > y1) ystep = 1;
            if (x2 > x1) xstep = 1;
            
            char charr = '/';
            if (ystep == xstep) charr = '\\';
            
            ll cury = y1 + ystep;
            ll curx = x1 + xstep;
            
            while (cury != y2) {
                grid[cury][curx] = charr;
                cury += ystep;
                curx += xstep;
            }
            
        }
    }
    
    auto sep = {'|', '/', '\\', '*'};
    
    for (ll i = 0; i < n; i++) {
        bool toggle = false;
        ll charcount = 0;
        for (ll j = 0; j < m-1; j++) {
            if (find(begin(sep), end(sep),grid[i][j]) != end(sep)) {
                toggle = true;
                if (grid[i][j] == '*' && count(grid[i].begin(), grid[i].end(), '*') == 1) toggle = false;
                charcount++;
            }
            
            if (charcount % 2 != 0 && toggle && grid[i][j+1] == '.') grid[i][j+1] = '#';
        }
        
    } 
    
    
    for (ll i = 0; i < n; i++) {
        for (ll j = 0; j < m; j++) {
            cout << grid[i][j];
        }
        cout << "\n";
    }
    
    return 0;
}

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