Modern art

input/code.cpp: In function 'int main()':
input/code.cpp:44:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   44 |         auto [x, y] = q.front();
      |              ^
input/code.cpp:47:19: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   47 |         for (auto [dx, dy] : vector<pair<int, int>>{{0, 1}, {1, 0}, {0, -1}, {-1, 0}}) {
      |                   ^

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

int main() {
    int A, P;
    cin >> A >> P;

    if (P % 2 != 0 || P < 2 * A || P > 4 * A) {
        cout << "IMPOSSIBLE" << endl;
        return 0;
    }

    bool possible = false;
    int w_opt = 0, h_opt = 0;

    for (int w = 1; w <= A; ++w) {
        for (int h = 1; h <= A; ++h) {
            if (2 * (w + h) == P && w * h >= A) {
                possible = true;
                w_opt = w;
                h_opt = h;
                break;
            }
        }
        if (possible) break;
    }

    if (!possible) {
        cout << "IMPOSSIBLE" << endl;
        return 0;
    }

    vector<string> grid(w_opt + 2, string(h_opt + 2, '0'));

    int count = A;
    queue<pair<int, int>> q;
    q.push({1, 1});
    grid[1][1] = '1';
    --count;

    while (!q.empty() && count > 0) {
        auto [x, y] = q.front();
        q.pop();

        for (auto [dx, dy] : vector<pair<int, int>>{{0, 1}, {1, 0}, {0, -1}, {-1, 0}}) {
            int nx = x + dx, ny = y + dy;
            if (nx > 0 && nx <= w_opt && ny > 0 && ny <= h_opt && grid[nx][ny] == '0') {
                grid[nx][ny] = '1';
                q.push({nx, ny});
                --count;
                if (count == 0) break;
            }
        }
    }

    cout << "POSSIBLE" << endl;
    for (const string& row : grid) {
        cout << row << endl;
    }

    return 0;
}

Test 1

Verdict: WRONG ANSWER

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: ACCEPTED

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: WRONG ANSWER

Test 19

Verdict: ACCEPTED

Test 20

Verdict: WRONG ANSWER

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: WRONG ANSWER

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: WRONG ANSWER

Test 27

Verdict: WRONG ANSWER

Test 28

Verdict: WRONG ANSWER

Test 29

Verdict: ACCEPTED

Test 30

Verdict: WRONG ANSWER

Test 31

Verdict: WRONG ANSWER

Test 32

Verdict: ACCEPTED

Test 33

Verdict: WRONG ANSWER

Test 34

Verdict: WRONG ANSWER

Test 35

Verdict: ACCEPTED

Test 36

Verdict: WRONG ANSWER

Test 37

Verdict: ACCEPTED

Test 38

Verdict: WRONG ANSWER

Test 39

Verdict: ACCEPTED

Test 40

Verdict: WRONG ANSWER

Test 41

Verdict: ACCEPTED

Test 42

Verdict: WRONG ANSWER

Test 43

Verdict: WRONG ANSWER

Test 44

Verdict: WRONG ANSWER

Test 45

Verdict: ACCEPTED

Test 46

Verdict: WRONG ANSWER

Test 47

Verdict: ACCEPTED

Test 48

Verdict: WRONG ANSWER

Test 49

Verdict: ACCEPTED

Test 50

Verdict: WRONG ANSWER