Problem p03361 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
using namespace std;

/* #pragma */
/*
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
*/

/*alias*/
#define F first
#define S second

#define y0 y3487465
#define y1 y8687969
#define j0 j1347829
#define j1 j234892
#define next asdnext
#define prev asdprev
#define itn int

/*template*/
template <class T> inline bool amax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline bool amin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}

/* func */
int GCD(int a, int b) { return b ? GCD(b, a % b) : a; }
long long GCD(long long a, long long b) { return b ? GCD(b, a % b) : a; }
int LCM(int a, int b) { return a * b / GCD(a, b); }
long long LCM(long long a, long long b) { return a * b / GCD(a, b); }

/*struct*/
struct aaa {
  aaa() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);
  };
} aaaaaaa;

/* const */
const int INF = 1001001001;
const long long LINF = 1001001001001001001ll;
const int MOD = 1e9 + 7; // 10^9
const double EPS = 1e-9;
// const int dx[] = { 1, 1, 0, -1, -1, -1, 0, 1 }, dy[] = { 0, 1, 1, 1, 0, -1,
// -1, -1 };
const int dx[] = {1, 0, -1, 0}, dy[] = {0, 1, 0, -1};
// Counterclockwise from the 6o'clock direction
// Take the x-axis downward and the y-axis right

// #define int long long

// g++ -std=c++14 -Wall --pedantic-errors -o template template.cpp
// g++ -std=c++14 -Wall --pedantic-errors template.cpp
// chcp 65001

signed main() {
  int h, w;
  cin >> h >> w;

  vector<vector<char>> c(h + 1, vector<char>(w + 1));

  int cnt{};
  for (int i = 1; i <= h; i++) {
    for (int j = 1; j <= w; j++)
      cin >> c[i][j];
  }
  for (int i = 1; i <= h; i++) {
    for (int j = 1; j <= w; j++) {
      if (c[i][j] == '#' && c[i][j - 1] != '#' && c[i - 1][j] != '#' &&
          c[i][j + 1] != '#' && c[i + 1][j] != '#')
        cnt++;
    }
  }
  if (cnt == 0)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}

Fixed submission:
#include <bits/stdc++.h>
using namespace std;

/* #pragma */
/*
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
*/

/*alias*/
#define F first
#define S second

#define y0 y3487465
#define y1 y8687969
#define j0 j1347829
#define j1 j234892
#define next asdnext
#define prev asdprev
#define itn int

/*template*/
template <class T> inline bool amax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline bool amin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}

/* func */
int GCD(int a, int b) { return b ? GCD(b, a % b) : a; }
long long GCD(long long a, long long b) { return b ? GCD(b, a % b) : a; }
int LCM(int a, int b) { return a * b / GCD(a, b); }
long long LCM(long long a, long long b) { return a * b / GCD(a, b); }

/*struct*/
struct aaa {
  aaa() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);
  };
} aaaaaaa;

/* const */
const int INF = 1001001001;
const long long LINF = 1001001001001001001ll;
const int MOD = 1e9 + 7; // 10^9
const double EPS = 1e-9;
// const int dx[] = { 1, 1, 0, -1, -1, -1, 0, 1 }, dy[] = { 0, 1, 1, 1, 0, -1,
// -1, -1 };
const int dx[] = {1, 0, -1, 0}, dy[] = {0, 1, 0, -1};
// Counterclockwise from the 6o'clock direction
// Take the x-axis downward and the y-axis right

// #define int long long

// g++ -std=c++14 -Wall --pedantic-errors -o template template.cpp
// g++ -std=c++14 -Wall --pedantic-errors template.cpp
// chcp 65001

signed main() {
  int h, w;
  cin >> h >> w;

  vector<vector<char>> c(h + 2, vector<char>(w + 2));

  int cnt{};
  for (int i = 1; i <= h; i++) {
    for (int j = 1; j <= w; j++)
      cin >> c[i][j];
  }
  for (int i = 1; i <= h; i++) {
    for (int j = 1; j <= w; j++) {
      if (c[i][j] == '#' && c[i][j - 1] != '#' && c[i - 1][j] != '#' &&
          c[i][j + 1] != '#' && c[i + 1][j] != '#')
        cnt++;
    }
  }
  if (cnt == 0)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}