Abandoned warehouse

#include<bits/stdc++.h>
using namespace std;
struct Cell {
    int x, y;
};
int n, m;
vector<vector<char>> warehouse;
vector<vector<bool>> visited;
vector<vector<Cell>> parent;
vector<vector<char>> direction;
int dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};
char dir[] = {'D', 'U', 'R', 'L'};
bool isValid(int x, int y) {
    return x >= 0 && x < n && y >= 0 && y < m && warehouse[x][y] != '#' && !visited[x][y];
}
int bfs(Cell start, Cell end) {
    queue<Cell> q;
    q.push(start);
    visited[start.x][start.y] = true;
    while (!q.empty()) {
        Cell cur = q.front();
        q.pop();
        if (cur.x == end.x && cur.y == end.y) {
            return 1;
        }
        for (int i = 0; i < 4; ++i) {
            int newX = cur.x + dx[i];
            int newY = cur.y + dy[i];
            if (isValid(newX, newY)) {
                visited[newX][newY] = true;
                parent[newX][newY] = cur;
                direction[newX][newY] = dir[i];
                q.push({newX, newY});
            }
        }
    }
    return 0;
}
void printPath(Cell start, Cell end) {
    vector<char> path;
    Cell cur = end;
    while (cur.x != start.x || cur.y != start.y) {
        path.push_back(direction[cur.x][cur.y]);
        cur = parent[cur.x][cur.y];
    }
    reverse(path.begin(), path.end());
    cout<<path.size() << endl;
    for (char step : path) {
        cout<<step;
    }
    cout<<"\n";
}
int main() {
    cin >> n >> m;
    warehouse.assign(n, vector<char>(m));
    visited.assign(n, vector<bool>(m, false));
    parent.assign(n, vector<Cell>(m, {-1, -1}));
    direction.assign(n, vector<char>(m));
    Cell start, end;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < m; ++j) {
           cin>>warehouse[i][j];
           if (warehouse[i][j] == 'A'){
               start ={i, j};
           }else if(warehouse[i][j] == 'B'){
               end ={i, j};
           }
        }
    }
    if (bfs(start, end)) {
        cout<<"YES\n";
        printPath(start, end);
    } else {
        cout<<"NO\n";
    }
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED