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

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cmath>
#include <complex>
#include <cstdint>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

#ifdef _DEBUG
#define DUMP(x) std::cerr << (#x) << " = " << (x) << "\\n"
#else
#define DUMP(x)
#endif
#define REP(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define EREP(i, a, b) for (int i = (int)(a); i <= (int)(b); ++i)
#define RREP(i, a, b) for (int i = (int)(a)-1; i >= (int)(b); --i)
#define rep(i, n) REP(i, 0, n)
#define erep(i, n) EREP(i, 0, n)
#define rrep(i, n) RREP(i, n, 0)
#define ALL(r) (r).begin(), (r).end()
#define pb push_back
#define eb emplace_back
#define fi first
#define se second

template <typename T> ostream &operator<<(ostream &os, const vector<T> &v) {
  os << "{";
  rep(i, v.size()) os << v[i] << (i == (int)v.size() - 1 ? "" : ", ");
  os << "}";
  return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  return (os << "(" << p.first << ", " << p.second << ")");
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const map<T, U> &m) {
  bool first = true;
  os << "{";
  for (const auto &e : m) {
    if (!first)
      os << ", ";
    os << "{" << e.first << ": " << e.second << "}";
    first = false;
  }
  os << "}";
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const set<T> &s) {
  os << "{";
  bool first = true;
  for (const auto &e : s) {
    if (!first)
      os << ", ";
    os << e;
    first = false;
  }
  os << "}";
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &s) {
  os << "{";
  bool first = true;
  for (const auto &e : s) {
    if (!first)
      os << ", ";
    os << e;
    first = false;
  }
  os << "}";
  return os;
}
template <typename T> T dup(T x, T y) { return (x + y - 1) / y; };
template <typename A, size_t N, typename T>
inline void arrayFill(A (&array)[N], const T &val) {
  std::fill((T *)array, (T *)(array + N), val);
}
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
struct in {
  const size_t n = 0;
  in() = default;
  in(size_t n) : n(n){};
  template <typename T> operator T() {
    T ret;
    cin >> ret;
    return ret;
  }
  template <typename T> operator vector<T>() {
    assert(n != 0);
    vector<T> ret(n);
    for (T &x : ret) {
      T tmp = in();
      x = tmp;
    }
    return ret;
  }
  template <typename T, typename U> operator pair<T, U>() {
    pair<T, U> ret;
    ret.first = in();
    ret.second = in();
    return ret;
  }
};

namespace fiore::impl {
template <typename T> inline void out_impl(const T &x, char end_char) {
  std::cout << x << end_char;
}
template <typename T> inline void out_impl(const vector<T> &x, char end_char) {
  bool first = true;
  for (const auto &e : x) {
    if (!first)
      std::cout << ' ';
    std::cout << e;
    first = false;
  }
  std::cout << end_char;
}
} // namespace fiore::impl
template <typename T> inline void out(const T &x) {
  fiore::impl::out_impl(x, '\\n');
};
template <typename T, typename U, typename... Args>
inline void out(const T &x, const U &y, const Args &...args) {
  fiore::impl::out_impl(x, ' ');
  out(y, args...);
}

using ll = int64_t;
using vint = vector<int32_t>;
using vvint = vector<vint>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vstr = vector<string>;
using pint = pair<int32_t, int32_t>;
using vpint = vector<pint>;
using pll = pair<ll, ll>;
using vpll = vector<pll>;
using setint = set<int32_t>;
using qint = queue<int32_t>;
using qpint = queue<pint>;

constexpr std::int32_t INF = 1001001001;
constexpr std::int64_t LINF = 1001001001001001001;

void Main() {
  ll h = in(), w = in(), m = in();
  vvll target(h);
  vll col_cnt(w, 0);
  rep(i, m) {
    ll x = in(), y = in();
    --x, --y;
    target[x].pb(y);
    ++col_cnt[y];
  }

  rep(i, h) { sort(ALL(target[i])); }

  ll max_col_cnt = *max_element(ALL(col_cnt));
  set<ll> st;
  rep(i, w) {
    if (col_cnt[i] == max_col_cnt) {
      st.insert(i);
    }
  }

  ll ans = 1;
  rep(i, h) {
    if (target[i].size() < st.size()) {
      chmax(ans, (ll)target[i].size() + max_col_cnt);
    } else {
      int flag = 1;
      for (auto e : st) {
        DUMP(e);
        if (!binary_search(ALL(target[i]), e)) {
          flag = 0;
        }
      }
      chmax(ans, (ll)target[i].size() + max_col_cnt - flag);
    }
  }
  out(ans);
}

signed main() {
  std::cin.tie(nullptr);
  std::ios_base::sync_with_stdio(false);
  std::cout << std::fixed << std::setprecision(15);
  Main();
  return 0;
}

Error: 0

Fixed submission:

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cmath>
#include <complex>
#include <cstdint>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

#ifdef _DEBUG
#define DUMP(x) std::cerr << (#x) << " = " << (x) << "\\n"
#else
#define DUMP(x)
#endif
#define REP(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define EREP(i, a, b) for (int i = (int)(a); i <= (int)(b); ++i)
#define RREP(i, a, b) for (int i = (int)(a)-1; i >= (int)(b); --i)
#define rep(i, n) REP(i, 0, n)
#define erep(i, n) EREP(i, 0, n)
#define rrep(i, n) RREP(i, n, 0)
#define ALL(r) (r).begin(), (r).end()
#define pb push_back
#define eb emplace_back
#define fi first
#define se second

template <typename T> ostream &operator<<(ostream &os, const vector<T> &v) {
  os << "{";
  rep(i, v.size()) os << v[i] << (i == (int)v.size() - 1 ? "" : ", ");
  os << "}";
  return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  return (os << "(" << p.first << ", " << p.second << ")");
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const map<T, U> &m) {
  bool first = true;
  os << "{";
  for (const auto &e : m) {
    if (!first)
      os << ", ";
    os << "{" << e.first << ": " << e.second << "}";
    first = false;
  }
  os << "}";
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const set<T> &s) {
  os << "{";
  bool first = true;
  for (const auto &e : s) {
    if (!first)
      os << ", ";
    os << e;
    first = false;
  }
  os << "}";
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &s) {
  os << "{";
  bool first = true;
  for (const auto &e : s) {
    if (!first)
      os << ", ";
    os << e;
    first = false;
  }
  os << "}";
  return os;
}
template <typename T> T dup(T x, T y) { return (x + y - 1) / y; };
template <typename A, size_t N, typename T>
inline void arrayFill(A (&array)[N], const T &val) {
  std::fill((T *)array, (T *)(array + N), val);
}
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
struct in {
  const size_t n = 0;
  in() = default;
  in(size_t n) : n(n){};
  template <typename T> operator T() {
    T ret;
    cin >> ret;
    return ret;
  }
  template <typename T> operator vector<T>() {
    assert(n != 0);
    vector<T> ret(n);
    for (T &x : ret) {
      T tmp = in();
      x = tmp;
    }
    return ret;
  }
  template <typename T, typename U> operator pair<T, U>() {
    pair<T, U> ret;
    ret.first = in();
    ret.second = in();
    return ret;
  }
};

namespace fiore::impl {
template <typename T> inline void out_impl(const T &x, char end_char) {
  std::cout << x << end_char;
}
template <typename T> inline void out_impl(const vector<T> &x, char end_char) {
  bool first = true;
  for (const auto &e : x) {
    if (!first)
      std::cout << ' ';
    std::cout << e;
    first = false;
  }
  std::cout << end_char;
}
} // namespace fiore::impl
template <typename T> inline void out(const T &x) {
  fiore::impl::out_impl(x, '\\n');
};
template <typename T, typename U, typename... Args>
inline void out(const T &x, const U &y, const Args &...args) {
  fiore::impl::out_impl(x, ' ');
  out(y, args...);
}

using ll = int64_t;
using vint = vector<int32_t>;
using vvint = vector<vint>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vstr = vector<string>;
using pint = pair<int32_t, int32_t>;
using vpint = vector<pint>;
using pll = pair<ll, ll>;
using vpll = vector<pll>;
using setint = set<int32_t>;
using qint = queue<int32_t>;
using qpint = queue<pint>;

constexpr std::int32_t INF = 1001001001;
constexpr std::int64_t LINF = 1001001001001001001;

void Main() {
  int h = in(), w = in(), m = in();
  vvint target(h);
  vector<bitset<300005>> bs(h);
  rep(i, h) rep(j, w) bs[i].set(j);
  vint col_cnt(w, 0);
  rep(i, m) {
    int x = in(), y = in();
    --x, --y;
    target[x].pb(y);
    bs[x].reset(y);
    ++col_cnt[y];
  }

  int max_col_cnt = *max_element(ALL(col_cnt));
  bitset<300005> bs2;
  set<int> st;
  rep(i, w) {
    if (col_cnt[i] == max_col_cnt) {
      bs2.set(i);
      st.insert(i);
    }
  }

  int ans = 1;
  rep(i, h) {
    if (target[i].size() < st.size()) {
      chmax(ans, (int)target[i].size() + max_col_cnt);
    } else {
      if ((bs[i] & bs2).any()) {
        chmax(ans, (int)target[i].size() + max_col_cnt);
      } else {
        chmax(ans, (int)target[i].size() + max_col_cnt - 1);
      }
    }
  }
  out(ans);
}

signed main() {
  std::cin.tie(nullptr);
  std::ios_base::sync_with_stdio(false);
  std::cout << std::fixed << std::setprecision(15);
  Main();
  return 0;
}