1185E - Polycarp and Snakes - CodeForces Solution

#include <bits/stdc++.h>
 
using namespace std;
 
typedef pair<int,int> ii;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ii> vii; 
typedef vector<vii> wgraf;
typedef pair<int,ii> edge;
typedef vector <ll> vl;
typedef pair <ll, ll> LL;
typedef vector <LL> vll;
 
#define UNVISITED 0
#define VISITED 1
#define pb push_back
#define F first
#define S second
 
void SOLVE(){
  ll n, m, a, b;
  
  cin >> n >> m;

  char matriz[n+5][m+5], arma[n+5][m+5], mayor='a'-1;

  memset(arma, '.', sizeof arma);
  map <char, vii> letras;

  for (ll i=1; i<=n; i++){
    for (ll j=1; j<=m; j++){
      cin >> matriz[i][j];
      if (matriz[i][j]!='.') {
        letras[matriz[i][j]].pb({i, j});
      }
    }
  }

  for (auto i:letras){
    bool fil=true, col=true;
    ll f=i.S[0].F, c=i.S[0].S;

    for (auto j:i.S){
      if (j.F!=f) fil=false;
      if (j.S!=c) col=false;
      if (fil==false && col==false) {
        cout << "NO\n";
        return;
      }
      a=j.F;
      b=j.S;
    }

    if (fil==true){
      for (ll j=c; j<=b; j++) arma[f][j]=i.F;
    } else {
      for (ll j=f; j<=a; j++) arma[j][c]=i.F;
    }

    mayor=i.F;
  }

  for (ll i=1; i<=n; i++){
    for (ll j=1; j<=m; j++) {
      if (matriz[i][j]!=arma[i][j]){
        cout << "NO\n";
        return;
      }
    }
  }

  cout << "YES\n";

  cout << max(mayor+1-'a', 0) << "\n";

  for (char i='a'; i<mayor+1; i++){

    if (letras[i].size()!=0)cout << letras[i][0].F << " " << letras[i][0].S << " " << letras[i][letras[i].size()-1].F << " " << letras[i][letras[i].size()-1].S << "\n";
    else cout << a << " " << b << " " << a << " " << b << "\n";

  }

}
 
int main(){
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int t = 1;
  cin >> t;
  while(t--){
    SOLVE();
  }
}