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

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

// エイリアス
using ll = long signed long;
using ull = long unsigned long;
using ld = long double;
using P = pair<int, int>;
using llP = pair<ll, ll>;
using DoP = pair<double, double>;

// 汎用マクロ
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define rep(i, n) for (int i = 0; i < n; ++i)
#define FOREACH(i, q) for (auto &i : q)
#define UNIQUE(v)                                                              \\
  do {                                                                         \\
    sort((v).begin(), (v).end());                                              \\
    (v).erase(unique((v).begin(), (v).end()), (v).end());                      \\
  } while (false)
#define SZ(x) ((int)(x).size())
template <class T> inline bool chmin(T &a, const T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmax(T &a, const T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline void line_out(const vector<T> vec) {
  int n = SZ(vec);
  rep(i, n) {
    cout << vec[i];
    if (i < n - 1)
      cout << " ";
  }
  cout << endl;
}
const int di[] = {0, 1, 0, -1, 1, 1, -1, -1};
const int dj[] = {1, 0, -1, 0, 1, -1, 1, -1};
const int di2[] = {1, 1, -1, -1, 0,  1,  2,  2,  2,  2,
                   2, 1, 0,  -1, -2, -2, -2, -2, -2, -1};
const int dj2[] = {1,  -1, 1,  -1, 2,  2,  2, 1, 0, -1,
                   -2, -2, -2, -2, -2, -1, 0, 1, 2, 2};
const int INF = 1 << 28;
const ll INF64 = 1ll << 55;
const int mod = 1000000007;
// const int mod = 998244353;
struct mint {
  ll x; // typedef long long ll;
  mint(ll x = 0) : x((x % mod + mod) % mod) {}
  mint operator-() const { return mint(-x); }
  mint &operator+=(const mint a) {
    if ((x += a.x) >= mod)
      x -= mod;
    return *this;
  }
  mint &operator-=(const mint a) {
    if ((x += mod - a.x) >= mod)
      x -= mod;
    return *this;
  }
  mint &operator*=(const mint a) {
    (x *= a.x) %= mod;
    return *this;
  }
  mint operator+(const mint a) const {
    mint res(*this);
    return res += a;
  }
  mint operator-(const mint a) const {
    mint res(*this);
    return res -= a;
  }
  mint &operator++() {
    if ((x += 1) >= mod)
      x -= mod;
    return *this;
  }
  mint &operator--() {
    if ((x += mod - 1) >= mod)
      x -= mod;
    return *this;
  }
  mint operator*(const mint a) const {
    mint res(*this);
    return res *= a;
  }
  mint pow(ll t) const {
    if (!t)
      return 1;
    mint a = pow(t >> 1);
    a *= a;
    if (t & 1)
      a *= *this;
    return a;
  }

  // for prime mod
  mint inv() const { return pow(mod - 2); }
  mint &operator/=(const mint a) { return (*this) *= a.inv(); }
  mint operator/(const mint a) const {
    mint res(*this);
    return res /= a;
  }
};

int main() {
  int h, w, m;
  cin >> h >> w >> m;
  vector<P> hv(h), wv(w);
  vector<P> point(m);
  rep(i, h) hv[i] = make_pair(0, i);
  rep(i, w) wv[i] = make_pair(0, i);

  rep(i, m) {
    int a, b;
    cin >> a >> b;
    --a;
    --b;
    ++hv[a].first;
    ++wv[b].first;
    point[i] = make_pair(a, b);
  }

  sort(ALL(hv));
  sort(ALL(wv));
  sort(ALL(point));
  int h_max = hv.back().first;
  int w_max = wv.back().first;

  for (auto it1 = lower_bound(ALL(hv), make_pair(h_max, 0)); it1 != hv.end();
       ++it1) {
    for (auto it2 = lower_bound(ALL(wv), make_pair(w_max, 0)); it2 != wv.end();
         ++it2) {
      int i = it1->second, j = it2->second;
      if (!binary_search(ALL(point), make_pair(i, j))) {
        cout << h_max + w_max << endl;
        return 0;
      }
    }
  }
  cout << h_max + w_max - 1 << endl;
}

Error: 0

Fixed submission:

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

// エイリアス
using ll = long signed long;
using ull = long unsigned long;
using ld = long double;
using P = pair<int, int>;
using llP = pair<ll, ll>;
using DoP = pair<double, double>;

// 汎用マクロ
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define rep(i, n) for (int i = 0; i < n; ++i)
#define FOREACH(i, q) for (auto &i : q)
#define UNIQUE(v)                                                              \\
  do {                                                                         \\
    sort((v).begin(), (v).end());                                              \\
    (v).erase(unique((v).begin(), (v).end()), (v).end());                      \\
  } while (false)
#define SZ(x) ((int)(x).size())
template <class T> inline bool chmin(T &a, const T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmax(T &a, const T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline void line_out(const vector<T> vec) {
  int n = SZ(vec);
  rep(i, n) {
    cout << vec[i];
    if (i < n - 1)
      cout << " ";
  }
  cout << endl;
}
const int di[] = {0, 1, 0, -1, 1, 1, -1, -1};
const int dj[] = {1, 0, -1, 0, 1, -1, 1, -1};
const int di2[] = {1, 1, -1, -1, 0,  1,  2,  2,  2,  2,
                   2, 1, 0,  -1, -2, -2, -2, -2, -2, -1};
const int dj2[] = {1,  -1, 1,  -1, 2,  2,  2, 1, 0, -1,
                   -2, -2, -2, -2, -2, -1, 0, 1, 2, 2};
const int INF = 1 << 28;
const ll INF64 = 1ll << 55;
const int mod = 1000000007;
// const int mod = 998244353;
struct mint {
  ll x; // typedef long long ll;
  mint(ll x = 0) : x((x % mod + mod) % mod) {}
  mint operator-() const { return mint(-x); }
  mint &operator+=(const mint a) {
    if ((x += a.x) >= mod)
      x -= mod;
    return *this;
  }
  mint &operator-=(const mint a) {
    if ((x += mod - a.x) >= mod)
      x -= mod;
    return *this;
  }
  mint &operator*=(const mint a) {
    (x *= a.x) %= mod;
    return *this;
  }
  mint operator+(const mint a) const {
    mint res(*this);
    return res += a;
  }
  mint operator-(const mint a) const {
    mint res(*this);
    return res -= a;
  }
  mint &operator++() {
    if ((x += 1) >= mod)
      x -= mod;
    return *this;
  }
  mint &operator--() {
    if ((x += mod - 1) >= mod)
      x -= mod;
    return *this;
  }
  mint operator*(const mint a) const {
    mint res(*this);
    return res *= a;
  }
  mint pow(ll t) const {
    if (!t)
      return 1;
    mint a = pow(t >> 1);
    a *= a;
    if (t & 1)
      a *= *this;
    return a;
  }

  // for prime mod
  mint inv() const { return pow(mod - 2); }
  mint &operator/=(const mint a) { return (*this) *= a.inv(); }
  mint operator/(const mint a) const {
    mint res(*this);
    return res /= a;
  }
};

int main() {
  int h, w, m;
  cin >> h >> w >> m;
  vector<P> hv(h), wv(w);
  vector<vector<bool>> flag(h, vector<bool>(w, false));
  rep(i, h) hv[i] = make_pair(0, i);
  rep(i, w) wv[i] = make_pair(0, i);
  rep(i, m) {
    int a, b;
    cin >> a >> b;
    --a;
    --b;
    ++hv[a].first;
    ++wv[b].first;
    flag[a][b] = true;
  }
  sort(ALL(hv));
  sort(ALL(wv));
  int h_max = hv.back().first;
  int w_max = wv.back().first;

  for (auto it1 = lower_bound(ALL(hv), make_pair(h_max, 0)); it1 != hv.end();
       ++it1) {
    for (auto it2 = lower_bound(ALL(wv), make_pair(w_max, 0)); it2 != wv.end();
         ++it2) {
      int i = it1->second, j = it2->second;
      if (!flag[i][j]) {
        cout << h_max + w_max << endl;
        return 0;
      }
    }
  }
  cout << h_max + w_max - 1 << endl;
}