Problem p02580 (C++) — buggy submission, verdict: Time Limit Exceeded

#include "bits/stdc++.h"
using namespace std;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using P = pair<int, int>;
using PL = pair<ll, ll>;
using vp = vector<P>;
using vpl = vector<PL>;
#define pqueue priority_queue
template <typename T> constexpr auto inf = numeric_limits<T>::max() / 2;
constexpr int INF = inf<int>, MOD = 1000000007;
constexpr ll LINF = inf<ll>;
#define _ol3(_1, _2, _3, name, ...) name
#define _rep(i, n) _repi(i, 0, n)
#define _repi(i, a, b) for (int i = a, i##_l = (b); i < i##_l; ++i)
#define REP(...) _ol3(__VA_ARGS__, _repi, _rep, )(__VA_ARGS__)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define REPA(i, v) REP(i, (v).size())
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define bit(n) (1ll << (n))
#define F first
#define S second
#define endl '\\n'
void _print(ostream &) {}
template <class T, class... U>
void _print(ostream &s, const T &t, const U &...u) {
  s << t << (sizeof...(u) ? ' ' : '\\n');
  _print(s, u...);
}
template <class... T> void print(const T &...t) { _print(cout, t...); }
template <class... T> void dprint(const T &...t) { _print(cerr, t...); }
#ifndef LOCAL
struct osd {
  template <class T> osd &operator<<(const T &t) { return *this; }
};
osd cer_;
#define dprint(...)
#define cerr cer_
#endif
#define dbg(x) dprint("@l", __LINE__, ':', #x, '=', x)
#define cho(n, a, b) print((n) ? a : b)
void YES(int n) { cho(n, "YES", "NO"); }
void Yes(int n) { cho(n, "Yes", "No"); }
void Poss(int n) { cho(n, "Possible", "Impossible"); }
template <class T, class U> bool chmax(T &a, const U &b) {
  bool x = a < b;
  x ? a = b : b;
  return x;
}
template <class T, class U> bool chmin(T &a, const U &b) {
  bool x = a > b;
  x ? a = b : b;
  return x;
}
template <class T, class U> auto max(const T &a, const U &b) {
  return a < b ? b : a;
}
template <class T, class U> auto min(const T &a, const U &b) {
  return a < b ? a : b;
}
template <class T, class U>
ostream &operator<<(ostream &o, const pair<T, U> &p) {
  return o << p.F << ' ' << p.S;
}
template <class T, class U> istream &operator>>(istream &i, pair<T, U> &p) {
  return i >> p.F >> p.S;
}
template <class T> class iterable {
  static false_type c(string v);
  template <class U> static auto c(U v) -> decltype(all(v), true_type());
  static false_type c(...);

public:
  const static bool value = decltype(c(declval<T>()))::value;
};
template <class T, enable_if_t<iterable<T>::value, int> = 0>
ostream &operator<<(ostream &o, const T &v) {
  for (auto &&i : v)
    o << i << ' ';
  return o;
}
template <class T> istream &operator>>(istream &i, vector<T> &v) {
  for (T &j : v)
    i >> j;
  return i;
}
template <class T> vector<T> &operator<<(vector<T> &v, const T &t) {
  v.push_back(t);
  return v;
}
template <class T, class U>
queue<T, U> &operator<<(queue<T, U> &v, const T &t) {
  v.push(t);
  return v;
}
template <class T, class U> queue<T, U> &operator>>(queue<T, U> &v, T &t) {
  t = v.front();
  v.pop();
  return v;
}
template <class T, class U, class V>
pqueue<T, U, V> &operator<<(pqueue<T, U, V> &v, const T &t) {
  v.push(t);
  return v;
}
template <class T, class U, class V>
pqueue<T, U, V> &operator>>(pqueue<T, U, V> &v, T &t) {
  t = v.front();
  v.pop();
  return v;
}
template <class T, class U>
stack<T, U> &operator<<(stack<T, U> &v, const T &t) {
  v.push(t);
  return v;
}
template <class T, class U> stack<T, U> &operator>>(stack<T, U> &v, T &t) {
  t = v.front();
  v.pop();
  return v;
}
template <class T, class U, class V>
set<T, U, V> &operator<<(set<T, U, V> &v, const T &t) {
  v.insert(t);
  return v;
}
template <class T, class U, class V>
multiset<T, U, V> &operator<<(multiset<T, U, V> &v, const T &t) {
  v.insert(t);
  return v;
}
template <class T, enable_if_t<is_integral<T>::value, int> = 0>
T mod(T a, T b) {
  if (a > 0)
    return a % b;
  return b - (-a % b);
}
template <class T, enable_if_t<is_floating_point<T>::value, int> = 0>
T mod(T a, T b) {
  if (a > 0)
    return fmod(a, b);
  return b - fmod(-a, b);
}
template <class T, class U>
pair<T, U> &operator+=(pair<T, U> &a, const pair<T, U> &b) {
  a.F += b.F;
  a.S += b.S;
  return a;
}
template <class T, class U>
pair<T, U> operator+(const pair<T, U> &a, const pair<T, U> &b) {
  auto r = a;
  return r += b;
}
template <class T, class U>
pair<T, U> &operator-=(pair<T, U> &a, const pair<T, U> &b) {
  a.F -= b.F;
  a.S -= b.S;
  return a;
}
template <class T, class U>
pair<T, U> operator-(const pair<T, U> &a, const pair<T, U> &b) {
  auto r = a;
  return r -= b;
}
template <class T, class U> pair<T, U> operator-(const pair<T, U> &a) {
  return {-a.F, -a.S};
}
template <class T, class U> double norm(const pair<T, U> &p) {
  return norm(p.F) + norm(p.S);
}
template <class T, class U> double abs(const pair<T, U> &p) {
  return sqrt(norm(p));
}

int solve(const vp &a) {
  const int m = a.size();
  map<int, int> x, y;
  REP(i, m) {
    x[a[i].F]++;
    y[a[i].S]++;
  }
  int xm = 0, xi;

  for (auto p : x) {
    if (chmax(xm, p.S))
      xi = p.F;
  }
  int ma = 0;
  for (auto p : y) {
    int c = xm + p.S;
    P s(xi, p.F);
    auto iter = lower_bound(all(a), s);
    if (iter != a.end() && *iter == s)
      --c;
    chmax(ma, c);
  }

  return ma;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(0);
  cout << fixed << setprecision(10);
  int h, w, m;
  cin >> h >> w >> m;
  vp a(m);
  cin >> a;
  int ma = 0;
  sort(all(a));
  chmax(ma, solve(a));
  REP(i, m) swap(a[i].F, a[i].S);
  sort(all(a));
  chmax(ma, solve(a));
  cout << ma << endl;
}


Error: TLE

Fixed submission:

#include "bits/stdc++.h"
using namespace std;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using P = pair<int, int>;
using PL = pair<ll, ll>;
using vp = vector<P>;
using vpl = vector<PL>;
#define pqueue priority_queue
template <typename T> constexpr auto inf = numeric_limits<T>::max() / 2;
constexpr int INF = inf<int>, MOD = 1000000007;
constexpr ll LINF = inf<ll>;
#define _ol3(_1, _2, _3, name, ...) name
#define _rep(i, n) _repi(i, 0, n)
#define _repi(i, a, b) for (int i = a, i##_l = (b); i < i##_l; ++i)
#define REP(...) _ol3(__VA_ARGS__, _repi, _rep, )(__VA_ARGS__)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define REPA(i, v) REP(i, (v).size())
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define bit(n) (1ll << (n))
#define F first
#define S second
#define endl '\\n'
void _print(ostream &) {}
template <class T, class... U>
void _print(ostream &s, const T &t, const U &...u) {
  s << t << (sizeof...(u) ? ' ' : '\\n');
  _print(s, u...);
}
template <class... T> void print(const T &...t) { _print(cout, t...); }
template <class... T> void dprint(const T &...t) { _print(cerr, t...); }
#ifndef LOCAL
struct osd {
  template <class T> osd &operator<<(const T &t) { return *this; }
};
osd cer_;
#define dprint(...)
#define cerr cer_
#endif
#define dbg(x) dprint("@l", __LINE__, ':', #x, '=', x)
#define cho(n, a, b) print((n) ? a : b)
void YES(int n) { cho(n, "YES", "NO"); }
void Yes(int n) { cho(n, "Yes", "No"); }
void Poss(int n) { cho(n, "Possible", "Impossible"); }
template <class T, class U> bool chmax(T &a, const U &b) {
  bool x = a < b;
  x ? a = b : b;
  return x;
}
template <class T, class U> bool chmin(T &a, const U &b) {
  bool x = a > b;
  x ? a = b : b;
  return x;
}
template <class T, class U> auto max(const T &a, const U &b) {
  return a < b ? b : a;
}
template <class T, class U> auto min(const T &a, const U &b) {
  return a < b ? a : b;
}
template <class T, class U>
ostream &operator<<(ostream &o, const pair<T, U> &p) {
  return o << p.F << ' ' << p.S;
}
template <class T, class U> istream &operator>>(istream &i, pair<T, U> &p) {
  return i >> p.F >> p.S;
}
template <class T> class iterable {
  static false_type c(string v);
  template <class U> static auto c(U v) -> decltype(all(v), true_type());
  static false_type c(...);

public:
  const static bool value = decltype(c(declval<T>()))::value;
};
template <class T, enable_if_t<iterable<T>::value, int> = 0>
ostream &operator<<(ostream &o, const T &v) {
  for (auto &&i : v)
    o << i << ' ';
  return o;
}
template <class T> istream &operator>>(istream &i, vector<T> &v) {
  for (T &j : v)
    i >> j;
  return i;
}
template <class T> vector<T> &operator<<(vector<T> &v, const T &t) {
  v.push_back(t);
  return v;
}
template <class T, class U>
queue<T, U> &operator<<(queue<T, U> &v, const T &t) {
  v.push(t);
  return v;
}
template <class T, class U> queue<T, U> &operator>>(queue<T, U> &v, T &t) {
  t = v.front();
  v.pop();
  return v;
}
template <class T, class U, class V>
pqueue<T, U, V> &operator<<(pqueue<T, U, V> &v, const T &t) {
  v.push(t);
  return v;
}
template <class T, class U, class V>
pqueue<T, U, V> &operator>>(pqueue<T, U, V> &v, T &t) {
  t = v.front();
  v.pop();
  return v;
}
template <class T, class U>
stack<T, U> &operator<<(stack<T, U> &v, const T &t) {
  v.push(t);
  return v;
}
template <class T, class U> stack<T, U> &operator>>(stack<T, U> &v, T &t) {
  t = v.front();
  v.pop();
  return v;
}
template <class T, class U, class V>
set<T, U, V> &operator<<(set<T, U, V> &v, const T &t) {
  v.insert(t);
  return v;
}
template <class T, class U, class V>
multiset<T, U, V> &operator<<(multiset<T, U, V> &v, const T &t) {
  v.insert(t);
  return v;
}
template <class T, enable_if_t<is_integral<T>::value, int> = 0>
T mod(T a, T b) {
  if (a > 0)
    return a % b;
  return b - (-a % b);
}
template <class T, enable_if_t<is_floating_point<T>::value, int> = 0>
T mod(T a, T b) {
  if (a > 0)
    return fmod(a, b);
  return b - fmod(-a, b);
}
template <class T, class U>
pair<T, U> &operator+=(pair<T, U> &a, const pair<T, U> &b) {
  a.F += b.F;
  a.S += b.S;
  return a;
}
template <class T, class U>
pair<T, U> operator+(const pair<T, U> &a, const pair<T, U> &b) {
  auto r = a;
  return r += b;
}
template <class T, class U>
pair<T, U> &operator-=(pair<T, U> &a, const pair<T, U> &b) {
  a.F -= b.F;
  a.S -= b.S;
  return a;
}
template <class T, class U>
pair<T, U> operator-(const pair<T, U> &a, const pair<T, U> &b) {
  auto r = a;
  return r -= b;
}
template <class T, class U> pair<T, U> operator-(const pair<T, U> &a) {
  return {-a.F, -a.S};
}
template <class T, class U> double norm(const pair<T, U> &p) {
  return norm(p.F) + norm(p.S);
}
template <class T, class U> double abs(const pair<T, U> &p) {
  return sqrt(norm(p));
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(0);
  cout << fixed << setprecision(10);
  int h, w, m;
  cin >> h >> w >> m;
  vp a(m);
  cin >> a;
  sort(all(a));
  map<int, int> x, y;
  REP(i, m) {
    x[a[i].F]++;
    y[a[i].S]++;
  }
  vp yp(all(y));
  sort(all(yp), [](P a, P b) { return a.S > b.S; });
  int ma = 0;
  REP(i, m) {
    int xx = a[i].F;
    REPA(j, yp) {
      /* if(yp[j].S==1)break; */
      if (yp[j].S < yp[0].S - 1)
        break;
      int c = x[xx] + yp[j].S;
      auto iter = lower_bound(all(a), P(xx, yp[j].F));
      if (iter != a.end() && *iter == P(xx, yp[j].F))
        --c;
      chmax(ma, c);
    }
  }
  cout << ma << endl;
}