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

#include <bits/stdc++.h>

#define rep(i, n) for (int i = 0; i < (n); ++i)

using namespace std;
typedef long long ll;
typedef pair<ll, ll> P;
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}

// 定数たち
const ll INF = 1e18;
const double PI = 3.14159265358979323846264338327950;

// 最大公約数
ll gcd(ll x, ll y) {
  ll tmp = 0;
  if (x < y) {
    tmp = x;
    x = y;
    y = tmp;
  }
  while (y > 0) {
    ll r = x % y;
    x = y;
    y = r;
  }
  return x;
}

// 最大公倍数
ll lcm(ll x, ll y) { return x / gcd(x, y) * y; }

const int MAX = 1e6 + 1;
const ll MOD = 1e9 + 7;

long long fac[MAX], finv[MAX], inv[MAX];

// テーブルを作る前処理
void COMinit() {
  fac[0] = fac[1] = 1;
  finv[0] = finv[1] = 1;
  inv[1] = 1;
  for (int i = 2; i < MAX; i++) {
    fac[i] = fac[i - 1] * i % MOD;
    inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
    finv[i] = finv[i - 1] * inv[i] % MOD;
  }
}

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*(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;
  }
};

// 二項係数計算
long long COM(int n, int k) {
  if (n < k)
    return 0;
  if (n < 0 || k < 0)
    return 0;
  return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}

// 階乗
ll kaijo(ll k) {
  ll sum = 1;
  for (ll i = 1; i <= k; ++i) {
    sum *= i;
    sum %= 1000000000 + 7;
  }
  return sum;
}

long long modpow(long long a, long long n, long long MOD) {
  long long res = 1;
  while (n > 0) {
    if (n & 1)
      res = res * a % MOD;
    a = a * a % MOD;
    n >>= 1;
  }
  return res;
}

struct UnionFind {
  vector<int> par;
  UnionFind(int n) : par(n, -1) {}
  int root(int x) {
    if (par[x] < 0)
      return x;
    else
      return par[x] = root(par[x]);
  }
  bool issame(int x, int y) { return root(x) == root(y); }
  bool merge(int x, int y) {
    x = root(x);
    y = root(y);
    if (x == y)
      return false;
    if (par[x] > par[y])
      swap(x, y); // merge technique
    par[x] += par[y];
    par[y] = x;
    return true;
  }
  ll size(int x) { return -par[root(x)]; }
};

// 二項係数（大きい値用）
ll count(int n, int a) {
  ll bunshi = 1;
  for (int i = 0; i < a; i++) {
    bunshi *= (n - i);
    bunshi %= MOD;
  }
  ll bunbo = 1;
  for (int i = 1; i < a + 1; i++) {
    bunbo *= i;
    bunbo %= MOD;
  }
  bunbo = modpow(bunbo, MOD - 2, MOD);
  return (bunshi * bunbo) % MOD;
}

// 約数列挙。約数をvector<ll>で返す。計算量はsqrt(n)。
vector<ll> divisor(ll n) {
  vector<ll> ret;
  for (ll i = 1; i * i <= n; i++) {
    if (n % i == 0) {
      ret.push_back(i);
      if (i * i != n)
        ret.push_back(n / i);
    }
  }
  sort(begin(ret), end(ret));
  return (ret);
}

// グラフ
struct edge {
  ll to, cost;
};
// typedef pair<ll,ll> P;
struct graph {
  ll V;
  vector<vector<edge>> G;
  vector<ll> d;

  graph(ll n) { init(n); }

  void init(ll n) {
    V = n;
    G.resize(V);
    d.resize(V);
    rep(i, V) { d[i] = INF; }
  }

  void add_edge(ll s, ll t, ll cost) {
    edge e;
    e.to = t, e.cost = cost;
    G[s].push_back(e);
  }

  void dijkstra(ll s) {
    rep(i, V) { d[i] = INF; }
    d[s] = 0;
    priority_queue<P, vector<P>, greater<P>> que;
    que.push(P(0, s));
    while (!que.empty()) {
      P p = que.top();
      que.pop();
      ll v = p.second;
      if (d[v] < p.first)
        continue;
      for (auto e : G[v]) {
        if (d[e.to] > d[v] + e.cost) {
          d[e.to] = d[v] + e.cost;
          que.push(P(d[e.to], e.to));
        }
      }
    }
  }
};

// ここから開始
int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};

int main() {
  int H, W, M;
  cin >> H >> W >> M;
  vector<int> h(M), w(M);
  vector<int> cntH(H), cntW(W);
  int maxH = 0;
  int maxW = 0;
  set<P> s;
  rep(i, M) {
    cin >> h[i] >> w[i];
    h[i]--;
    w[i]--;
    cntH[h[i]]++;
    cntW[w[i]]++;
    s.emplace(h[i], w[i]);
  }
  vector<int> Hidx, Widx;
  rep(i, H) maxH = max(maxH, cntH[i]);
  rep(i, W) maxW = max(maxW, cntW[i]);
  rep(i, H) if (maxH == cntH[i]) Hidx.push_back(i);
  rep(i, W) if (maxW == cntW[i]) Widx.push_back(i);
  ll ans = maxH + maxW;
  for (int i : Hidx) {
    for (int j : Widx) {
      if (s.count(P(i, j)))
        continue;
      cout << ans << endl;
      return 0;
    }
  }
  cout << ans - 1 << endl;
  return 0;
}

Error: TLE

Fixed submission:

#include <bits/stdc++.h>

#define rep(i, n) for (int i = 0; i < (n); ++i)

using namespace std;
typedef pair<int, int> P;
typedef long long ll;
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}

// 最大公約数
ll gcd(ll x, ll y) {
  ll tmp = 0;
  if (x < y) {
    tmp = x;
    x = y;
    y = tmp;
  }
  while (y > 0) {
    ll r = x % y;
    x = y;
    y = r;
  }
  return x;
}

// 最大公倍数
ll lcm(ll x, ll y) { return x / gcd(x, y) * y; }

const int MAX = 1e6 + 1;
const ll MOD = 1e9 + 7;

long long fac[MAX], finv[MAX], inv[MAX];

// テーブルを作る前処理
void COMinit() {
  fac[0] = fac[1] = 1;
  finv[0] = finv[1] = 1;
  inv[1] = 1;
  for (int i = 2; i < MAX; i++) {
    fac[i] = fac[i - 1] * i % MOD;
    inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
    finv[i] = finv[i - 1] * inv[i] % MOD;
  }
}

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*(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;
  }
};

// 二項係数計算
long long COM(int n, int k) {
  if (n < k)
    return 0;
  if (n < 0 || k < 0)
    return 0;
  return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}

// 階乗
ll kaijo(ll k) {
  ll sum = 1;
  for (ll i = 1; i <= k; ++i) {
    sum *= i;
    sum %= 1000000000 + 7;
  }
  return sum;
}

long long modpow(long long a, long long n, long long MOD) {
  long long res = 1;
  while (n > 0) {
    if (n & 1)
      res = res * a % MOD;
    a = a * a % MOD;
    n >>= 1;
  }
  return res;
}

// //sieve(MAX);でベクトルIsPrimeに「MAXまでの数値の素数の真偽」を格納する。
// struct Sieve {
//     int n;
//     vector<int> f, primes;
//     Sieve(int n=1):n(n), f(n+1) {
//         f[0] = f[1] = -1;
//         for (ll i = 2; i <= n; ++i) {
//         if (f[i]) continue;
//         primes.push_back(i);
//         f[i] = i;
//         for (ll j = i*i; j <= n; j += i) {
//             if (!f[j]) f[j] = i;
//         }
//         }
//     }
//     bool isPrime(int x) { return f[x] == x;}
//     vector<int> factorList(int x) {
//         vector<int> res;
//         while (x != 1) {
//         res.push_back(f[x]);
//         x /= f[x];
//         }
//         return res;
//     }
//     vector<P> factor(int x) {
//         vector<int> fl = factorList(x);
//         if (fl.size() == 0) return {};
//         vector<P> res(1, P(fl[0], 0));
//         for (int p : fl) {
//         if (res.back().first == p) {
//             res.back().second++;
//         } else {
//             res.emplace_back(p, 1);
//         }
//         }
//         return res;
//     }
// };
struct UnionFind {
  vector<int> par;
  UnionFind(int n) : par(n, -1) {}
  int root(int x) {
    if (par[x] < 0)
      return x;
    else
      return par[x] = root(par[x]);
  }
  bool issame(int x, int y) { return root(x) == root(y); }
  bool merge(int x, int y) {
    x = root(x);
    y = root(y);
    if (x == y)
      return false;
    if (par[x] > par[y])
      swap(x, y); // merge technique
    par[x] += par[y];
    par[y] = x;
    return true;
  }
  ll size(int x) { return -par[root(x)]; }
};

// 二項係数（大きい値用）
ll count(int n, int a) {
  ll bunshi = 1;
  for (int i = 0; i < a; i++) {
    bunshi *= (n - i);
    bunshi %= MOD;
  }
  ll bunbo = 1;
  for (int i = 1; i < a + 1; i++) {
    bunbo *= i;
    bunbo %= MOD;
  }
  bunbo = modpow(bunbo, MOD - 2, MOD);
  // cout<<(bunshi*bunbo)%MOD<<endl;
  return (bunshi * bunbo) % MOD;
}

// 約数列挙。約数をvector<ll>で返す。計算量はsqrt(n)。
vector<ll> divisor(ll n) {
  vector<ll> ret;
  for (ll i = 1; i * i <= n; i++) {
    if (n % i == 0) {
      ret.push_back(i);
      if (i * i != n)
        ret.push_back(n / i);
    }
  }
  sort(begin(ret), end(ret));
  return (ret);
}

// ここから開始
const ll INF = 1e18;
const double PI = 3.14159265358979323846264338327950;
int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};

int main() {
  // cout<<"OK";
  map<pair<int, int>, bool> m;
  int H, W, M;
  cin >> H >> W >> M;
  set<pair<int, int>> se;
  vector<ll> hcnt(H);
  vector<ll> wcnt(W);

  rep(i, M) {
    int h, w;
    cin >> h >> w;
    h--;
    w--;
    se.insert(make_pair(h, w));
    hcnt[h]++;
    wcnt[w]++;
    m.insert(make_pair(make_pair(h, w), true));
  }

  ll ans = 0;
  rep(i, H) rep(j, W) {
    ll can = hcnt[i] + wcnt[j];
    if (m[make_pair(i, j)] == true)
      can--;
    ans = max(ans, can);
  }
  cout << ans << endl;
  return 0;
}