### anujnaruka02's blog

By anujnaruka02, history, 3 months ago,

My solution is giving wrong output. Any suggestions to help me in this. My code is as follows —

int main(){
int n,m;
cin>>n>>m;

vector<vector<char>> v(n,vector<char>(m));
vector<vector<int>> vis(n,vector<int>(m,0));
vector<vector<int>> prevs(n,vector<int>(m));
queue<pair<int,int>> q;
pair<int,int> start,end;

int delrow[] = {-1,0,1,0};
int delcol[] = {0,1,0,-1};
string dir = "URDL";

for(int i = 0; i<n; i++){
for(int j = 0; j<m; j++){
cin>>v[i][j];

if(v[i][j] == 'A'){
start = {i,j};
}
else if(v[i][j] == 'B'){
end = {i,j};
}
}
}

q.push({start.first,start.second});
vis[start.first][start.second] = 1;

while(!q.empty()){
int row = q.front().first;
int col = q.front().second;
q.pop();

for(int i = 0; i<4; i++){
int nrow = row + delrow[i];
int ncol = col + delcol[i];

if(nrow>=0 && nrow<n && ncol>=0 && ncol<n && !vis[nrow][ncol] && v[nrow][ncol] != '#'){
vis[nrow][ncol] = 1;
prevs[nrow][ncol] = i;
q.push({nrow,ncol});
}
}
}

if(vis[end.first][end.second] == 1){
cout << "YES" << endl;
vector<int> steps;
while(end.first != start.first || end.second != start.second){
int p = prevs[end.first][end.second];
steps.push_back(p);

end.first = end.first - delrow[p];
end.second = end.second - delcol[p];
}

reverse(steps.begin(),steps.end());

cout << steps.size() << endl;
for(auto it : steps){
cout << dir[it];
}
cout << endl;
}
else{
cout << "NO" << endl;
}
return 0;
}

• +8