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

#include <bits/stdc++.h>
#define ll long long
#define all(v) v.begin(), v.end()
#define PB push_back
#define PI 3.1415926535897932384626433832795
#define what(x) cout << #x << " is " << x << endl;
using namespace std;

template <typename A, typename B> string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string &s) { return '"' + s + '"'; }

string to_string(const char *s) { return to_string((string)s); }

string to_string(bool b) { return (b ? "true" : "false"); }

string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}

template <size_t N> string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}

template <typename A> string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}

template <typename A, typename B> string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}
#ifndef ONLINE_JUDGE
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

ll powmod(ll a, ll b, ll mod) {
  ll res = 1;
  a %= mod;
  // assert(b>=0);
  for (; b; b >>= 1) {
    if (b & 1)
      res = res * a % mod;
    a = a * a % mod;
  }
  return res;
}
map<int, int> hor, ver;
map<pair<int, int>, int> arr;
void solve() {
  int H, W, M;
  cin >> H >> W >> M;
  for (int x, y, i = 0; i < M; i++) {
    cin >> x >> y;
    arr[make_pair(x, y)]++;
    hor[x]++, ver[y]++;
  }
  int xmx = 0, ymx = 0;
  vector<int> xm, ym;
  for (auto it : hor) {
    xmx = max(xmx, it.second);
  }
  for (auto it : hor) {
    if (xmx == it.second)
      xm.push_back(it.first);
  }
  for (auto it : ver) {
    ymx = max(ymx, it.second);
  }
  for (auto it : ver) {
    if (ymx == it.second)
      ym.push_back(it.first);
  }
  int ans = 0, mx = xmx + ymx;
  for (int i = 0; ans != mx && i < (int)xm.size(); i++) {
    for (int j = 0; ans != mx && j < (int)ym.size(); j++) {
      ans = max(ans, hor[xm[i]] + ver[ym[j]] - arr[make_pair(xm[i], ym[j])]);
    }
  }
  cout << ans << '\\n';
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int tc = 1;
#ifndef ONLINE_JUDGE
  freopen("input.txt", "r", stdin);
#endif
  // cin>>tc;
  while (tc--)
    solve();
}


Error: -6
terminate called after throwing an instance of 'std::bad_alloc'
  what():  std::bad_alloc


Fixed submission:

#include <bits/stdc++.h>
#define ll long long
#define all(v) v.begin(), v.end()
#define PB push_back
#define PI 3.1415926535897932384626433832795
#define what(x) cout << #x << " is " << x << endl;
using namespace std;

template <typename A, typename B> string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string &s) { return '"' + s + '"'; }

string to_string(const char *s) { return to_string((string)s); }

string to_string(bool b) { return (b ? "true" : "false"); }

string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}

template <size_t N> string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}

template <typename A> string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}

template <typename A, typename B> string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}
#ifndef ONLINE_JUDGE
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

ll powmod(ll a, ll b, ll mod) {
  ll res = 1;
  a %= mod;
  // assert(b>=0);
  for (; b; b >>= 1) {
    if (b & 1)
      res = res * a % mod;
    a = a * a % mod;
  }
  return res;
}
const int mxn = 3e5 + 1;
vector<int> arr[mxn], hor, ver;
void solve() {
  int H, W, M;
  cin >> H >> W >> M;
  ver.resize(W + 1);
  hor.resize(H + 1);
  for (int i = 1; i <= H; i++) {
    arr[i].resize(W + 1);
  }
  for (int i = 0, x, y; i < M; i++) {
    cin >> x >> y;
    arr[x][y]++;
    hor[x]++, ver[y]++;
  }
  ll ans = 0;
  for (int i = 1; i <= H; i++) {
    for (int j = 1; j <= W; j++) {
      ans = max(ans, (ll)(hor[i] + ver[j] - arr[i][j]));
    }
  }
  cout << ans << '\\n';
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int tc = 1;
#ifndef ONLINE_JUDGE
  freopen("input.txt", "r", stdin);
#endif
  // cin>>tc;
  while (tc--)
    solve();
}