Revise paste Untitled

#include <iostream>
//#include <bits/stdc+/+.h>
#include <vector>
#include <queue>
#include <cstring>
#define ll long long

using namespace std;
int n,m;
int main()
{
int n,m;
cin >> n >> m;
char mat[n][m];
int di[]={-1,1,0,0};
int dj[]={0,0,1,-1};
int si,sj,ei,ej;
int k;cin>>k;
for(int i=0;i<n;i++){
    for(int j=0;j<m;j++){
        cin >> mat[i][j];
        if(mat[i][j] == 'M'){
            si =i;
            sj = j;
        }
        if(mat[i][j] == 'V'){
            ei =i;
            ej = j;
        }
    }
}
queue<int>q;
vector<vector<bool>> visited(n+1,vector<bool>(m+1,false));
q.push(si);
q.push(sj);
visited[si][sj]=true;
vector<pair<int,int>> cell;
int dist[n][m];
while(!q.empty()){
    int ci = q.front();
    q.pop();
    int cj = q.front();
    q.pop();
    visited[ci][cj] = true;
    if(mat[ci][cj] == 'V'){
        cout << "DA"<<endl;
        return 0;
    }
    for(int i =0;i<4;i++){
        int ti = ci+di[i];
        int tj = cj+dj[i];
        if(ti>=0 and ti<n and tj>=0 and tj<m and !visited[ti][tj]){
            if(mat[ti][tj] == '#'){
                cell.push_back(make_pair(ci,cj));
            }
            else{
            q.push(ti);
            q.push(tj);
            visited[ti][tj]=true;
            }
        }
    }
}
for(int i = 0;i<n+1;i++){
    for(int j =0;j<m+1;j++){
        visited[i][j] =false;
    }
}
for(int i =0;i<cell.size();i++){
    int ci = cell[i].first;
    int cj = cell[i].second;
    dist[ci][cj]=0;
    q.push(ci);
    q.push(cj);
    q.push(0);
    visited[ci][cj] =true;
}

while(!q.empty()){
    int ci = q.front();
    q.pop();
    int cj = q.front();
    q.pop();
    int pat = q.front();
    q.pop();

dist[ci][cj] = pat;
    for(int i =0;i<4;i++){
        int ti = ci+di[i];
        int tj = cj+dj[i];
        if(ti>=0 and ti<n and tj>=0 and tj<m and !visited[ti][tj]){
            q.push(ti);
            q.push(tj);
            q.push(pat+1);
            dist[ti][tj] = pat+1;
            visited[ti][tj] = true;
        }
    }

}
for(int i = 0;i<n+1;i++){
    for(int j =0;j<m+1;j++){
        visited[i][j] =false;
    }
}
q.push(ei);
q.push(ej);
visited[ei][ej] = true;
while(!q.empty()){
    int ci = q.front();
    q.pop();
    int cj =  q.front();
    q.pop();

if(dist[ci][cj]<=k){
        cout << "DA";
        return 0;
    }
    for(int i =0;i<4;i++){
        int ti =ci +di[i];
        int tj = cj+dj[i];

if(ti>=0 and ti<n and tj>=0 and tj<m and  !visited[ti][tj] and mat[ti][tj]!='#'){
            q.push(ti);
            q.push(tj);
            visited[ti][tj] =true;
        }
    }
}
cout << "NE";
}