Problem p02580 (C++) — buggy submission, verdict: Runtime Error

// Best practice

#include <bits/stdc++.h>

#define int long long
#define pb push_back
#define pf emplace_front
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define pii pair<int, int>
#define psi pair<string, int>
#define vi vector<int>
#define vpii vector<pii>
#define vvi vector<vi>
#define sz(x) (int)(x).size()
#define x first
#define y second
#define endl '\\n'
#define tezz                                                                   \\
  ios_base::sync_with_stdio(false);                                            \\
  cin.tie(0);                                                                  \\
  cout.tie(0);
#define MOD 1000000007
#define hell 998244353
#define prec(n) fixed << setprecision(n)
#define ini(a, i) memset(a, i, sizeof(a))
#define output(x) cout << (x ? "YES" : "NO") << endl;
using namespace std;

#define debug(vec)                                                             \\
  cout << (#vec) << " : [ ";                                                   \\
  for (auto &i : vec)                                                          \\
    cout << i << " ";                                                          \\
  cout << "]" << endl
#define debugp(vec)                                                            \\
  cout << (#vec) << " : [ ";                                                   \\
  for (auto &i : vec)                                                          \\
    cout << "(" << i.x << "," << i.y << ")"                                    \\
         << " ";                                                               \\
  cout << "]" << endl
#define trace(args...)                                                         \\
  {                                                                            \\
    string _s = #args;                                                         \\
    replace(_s.begin(), _s.end(), ',', ' ');                                   \\
    stringstream _ss(_s);                                                      \\
    istream_iterator<string> _it(_ss);                                         \\
    err(_it, args);                                                            \\
    cout << endl;                                                              \\
  }
void err(istream_iterator<string> it) {}
template <typename T, typename... Args>
void err(istream_iterator<string> it, T a, Args... args) {
  cout << "[" << *it << ": " << a << "]\\t";
  err(++it, args...);
}

// const int dx[4] = { -1, 1, 0, 0};
// const int dy[4] = {0, 0, -1, 1};
// int dX[] = { -1, -1, -1, 0, 0, 1, 1, 1 };
// int dY[] = { -1, 0, 1, -1, 1, -1, 0, 1 };

// Code from Here
// -------------------------------------------------------------------------------

signed main() {
  tezz

      int n,
      m, k, x, y;
  cin >> n >> m >> k;
  int a[n], b[m];
  ini(a, 0);
  ini(b, 0);
  int c, d;
  c = d = 0;
  map<pii, int> mp;
  for (int i = 0; i < k; i++) {
    cin >> x >> y;
    x--;
    y--;
    a[x]++;
    b[y]++;
    c = max(c, a[x]);
    d = max(d, b[y]);
    mp[{x, y}]++;
  }
  vi arr, brr;
  int ans = c + d - 1;
  for (int i = 0; i < n; i++) {
    if (a[i] == c)
      arr.pb(i);
  }
  for (int i = 0; i < m; i++) {
    if (b[i] == d)
      brr.pb(i);
  }
  for (int i = 0; i < sz(arr); i++) {
    for (int j = 0; j < sz(brr); j++) {
      if (!mp[{arr[i], brr[j]}]) {
        cout << ans + 1 << endl;
        return 0;
      }
    }
  }
  cout << ans << endl;

  return 0;
}

Error: 0

Fixed submission:

// Best practice

#include <bits/stdc++.h>

#define int long long
#define pb push_back
#define pf emplace_front
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define pii pair<int, int>
#define psi pair<string, int>
#define vi vector<int>
#define vpii vector<pii>
#define vvi vector<vi>
#define sz(x) (int)(x).size()
#define x first
#define y second
#define endl '\\n'
#define tezz                                                                   \\
  ios_base::sync_with_stdio(false);                                            \\
  cin.tie(0);                                                                  \\
  cout.tie(0);
#define MOD 1000000007
#define hell 998244353
#define prec(n) fixed << setprecision(n)
#define ini(a, i) memset(a, i, sizeof(a))
#define output(x) cout << (x ? "YES" : "NO") << endl;
using namespace std;

#define debug(vec)                                                             \\
  cout << (#vec) << " : [ ";                                                   \\
  for (auto &i : vec)                                                          \\
    cout << i << " ";                                                          \\
  cout << "]" << endl
#define debugp(vec)                                                            \\
  cout << (#vec) << " : [ ";                                                   \\
  for (auto &i : vec)                                                          \\
    cout << "(" << i.x << "," << i.y << ")"                                    \\
         << " ";                                                               \\
  cout << "]" << endl
#define trace(args...)                                                         \\
  {                                                                            \\
    string _s = #args;                                                         \\
    replace(_s.begin(), _s.end(), ',', ' ');                                   \\
    stringstream _ss(_s);                                                      \\
    istream_iterator<string> _it(_ss);                                         \\
    err(_it, args);                                                            \\
    cout << endl;                                                              \\
  }
void err(istream_iterator<string> it) {}
template <typename T, typename... Args>
void err(istream_iterator<string> it, T a, Args... args) {
  cout << "[" << *it << ": " << a << "]\\t";
  err(++it, args...);
}

// const int dx[4] = { -1, 1, 0, 0};
// const int dy[4] = {0, 0, -1, 1};
// int dX[] = { -1, -1, -1, 0, 0, 1, 1, 1 };
// int dY[] = { -1, 0, 1, -1, 1, -1, 0, 1 };

// Code from Here
// -------------------------------------------------------------------------------

signed main() {
  tezz

      int n,
      m, k, x, y;
  cin >> n >> m >> k;
  int a[n], b[m], arr[n][m];
  ini(a, 0);
  ini(b, 0);
  ini(arr, 0);
  for (int i = 0; i < k; i++) {
    cin >> x >> y;
    x--;
    y--;
    a[x]++;
    b[y]++;
    arr[x][y]++;
  }
  int ans = 0;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      ans = max(ans, a[i] + b[j] - (arr[i][j]));
    }
  }
  cout << ans << endl;

  return 0;
}