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

#include <algorithm>
#include <bits/stdc++.h>
#include <cstdio>
#include <iostream>
#define ALL(x) (x).begin(), (x).end()
#define sz(a) int(a.size())
#define rep(i, x, n) for (int i = x; i < n; i++)
#define repd(i, x, n) for (int i = x; i <= n; i++)
#define pii pair<int, int>
#define pll pair<long long, long long>
#define gbtb ios::sync_with_stdio(false), cin.tie(0), cout.tie(0)
#define MS0(X) memset((X), 0, sizeof((X)))
#define MSC0(X) memset((X), '\\0', sizeof((X)))
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define eps 1e-6
#define chu(x)                                                                 \\
  if (DEBUG_Switch)                                                            \\
  cout << "[" << #x << " " << (x) << "]" << endl
#define du3(a, b, c) scanf("%d %d %d", &(a), &(b), &(c))
#define du2(a, b) scanf("%d %d", &(a), &(b))
#define du1(a) scanf("%d", &(a));
using namespace std;
typedef long long ll;
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }
ll powmod(ll a, ll b, ll MOD) {
  if (a == 0ll) {
    return 0ll;
  }
  a %= MOD;
  ll ans = 1;
  while (b) {
    if (b & 1) {
      ans = ans * a % MOD;
    }
    a = a * a % MOD;
    b >>= 1;
  }
  return ans;
}
ll poww(ll a, ll b) {
  if (a == 0ll) {
    return 0ll;
  }
  ll ans = 1;
  while (b) {
    if (b & 1) {
      ans = ans * a;
    }
    a = a * a;
    b >>= 1;
  }
  return ans;
}
void Pv(const vector<int> &V) {
  int Len = sz(V);
  for (int i = 0; i < Len; ++i) {
    printf("%d", V[i]);
    if (i != Len - 1) {
      printf(" ");
    } else {
      printf("\\n");
    }
  }
}
void Pvl(const vector<ll> &V) {
  int Len = sz(V);
  for (int i = 0; i < Len; ++i) {
    printf("%lld", V[i]);
    if (i != Len - 1) {
      printf(" ");
    } else {
      printf("\\n");
    }
  }
}
inline long long readll() {
  long long tmp = 0, fh = 1;
  char c = getchar();
  while (c < '0' || c > '9') {
    if (c == '-')
      fh = -1;
    c = getchar();
  }
  while (c >= '0' && c <= '9')
    tmp = tmp * 10 + c - 48, c = getchar();
  return tmp * fh;
}
inline int readint() {
  int tmp = 0, fh = 1;
  char c = getchar();
  while (c < '0' || c > '9') {
    if (c == '-')
      fh = -1;
    c = getchar();
  }
  while (c >= '0' && c <= '9')
    tmp = tmp * 10 + c - 48, c = getchar();
  return tmp * fh;
}
void pvarr_int(int *arr, int n, int strat = 1) {
  if (strat == 0) {
    n--;
  }
  repd(i, strat, n) { printf("%d%c", arr[i], i == n ? '\\n' : ' '); }
}
void pvarr_LL(ll *arr, int n, int strat = 1) {
  if (strat == 0) {
    n--;
  }
  repd(i, strat, n) { printf("%lld%c", arr[i], i == n ? '\\n' : ' '); }
}
const int maxn = 500010;
const int inf = 0x3f3f3f3f;
/*** TEMPLATE CODE * * STARTS HERE ***/
#define DEBUG_Switch 0
std::vector<int> v[maxn];
ll n, m;
ll q;
struct node {
  ll id;
  ll val;
  node() {}
  node(ll y, ll v) {
    id = y;
    val = v;
  }
  bool operator<(const node &bb) const {
    if (val != bb.val)
      return val > bb.val;
    else
      return id > bb.id;
  }
};
set<node> st2;
ll cnt_row[maxn];
ll cnt_col[maxn];
int main() {
#if DEBUG_Switch
  freopen("C:\\\\code\\\\input.txt", "r", stdin);
#endif
  // freopen("C:\\\\code\\\\output.txt","w",stdout);
  n = readint();
  m = readint();
  q = readll();
  repd(i, 1, q) {
    int x = readint();
    int y = readint();
    cnt_row[x]++;
    cnt_col[y]++;
    v[x].push_back(y);
  }
  repd(i, 1, m) { st2.insert(node(i, cnt_col[i])); }
  ll ans = 1;
  repd(i, 1, n) {
    ll temp = cnt_row[i];
    for (auto y : v[i]) {
      ans = max(ans, temp + cnt_col[y] - 1);
      st2.erase(st2.lower_bound(node(y, cnt_col[y])));
    }
    if (st2.empty()) {
      for (auto y : v[i]) {
        st2.insert(node(y, cnt_col[y]));
      }
      continue;
    }
    auto it = st2.begin();
    if (it == st2.end()) {
      for (auto y : v[i]) {
        st2.insert(node(y, cnt_col[y]));
      }
      continue;
    }
    node now = *it;
    ans = max(ans, temp + now.val);
    for (auto y : v[i]) {
      st2.insert(node(y, cnt_col[y]));
    }
  }
  printf("%lld\\n", ans);
  return 0;
}


Error: TLE

Fixed submission:

#include <algorithm>
#include <bits/stdc++.h>
#include <cstdio>
#include <iostream>
#define ALL(x) (x).begin(), (x).end()
#define sz(a) int(a.size())
#define rep(i, x, n) for (int i = x; i < n; i++)
#define repd(i, x, n) for (int i = x; i <= n; i++)
#define pii pair<int, int>
#define pll pair<long long, long long>
#define gbtb ios::sync_with_stdio(false), cin.tie(0), cout.tie(0)
#define MS0(X) memset((X), 0, sizeof((X)))
#define MSC0(X) memset((X), '\\0', sizeof((X)))
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define eps 1e-6
#define chu(x)                                                                 \\
  if (DEBUG_Switch)                                                            \\
  cout << "[" << #x << " " << (x) << "]" << endl
#define du3(a, b, c) scanf("%d %d %d", &(a), &(b), &(c))
#define du2(a, b) scanf("%d %d", &(a), &(b))
#define du1(a) scanf("%d", &(a));
using namespace std;
typedef long long ll;
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }
ll powmod(ll a, ll b, ll MOD) {
  if (a == 0ll) {
    return 0ll;
  }
  a %= MOD;
  ll ans = 1;
  while (b) {
    if (b & 1) {
      ans = ans * a % MOD;
    }
    a = a * a % MOD;
    b >>= 1;
  }
  return ans;
}
ll poww(ll a, ll b) {
  if (a == 0ll) {
    return 0ll;
  }
  ll ans = 1;
  while (b) {
    if (b & 1) {
      ans = ans * a;
    }
    a = a * a;
    b >>= 1;
  }
  return ans;
}
void Pv(const vector<int> &V) {
  int Len = sz(V);
  for (int i = 0; i < Len; ++i) {
    printf("%d", V[i]);
    if (i != Len - 1) {
      printf(" ");
    } else {
      printf("\\n");
    }
  }
}
void Pvl(const vector<ll> &V) {
  int Len = sz(V);
  for (int i = 0; i < Len; ++i) {
    printf("%lld", V[i]);
    if (i != Len - 1) {
      printf(" ");
    } else {
      printf("\\n");
    }
  }
}
inline long long readll() {
  long long tmp = 0, fh = 1;
  char c = getchar();
  while (c < '0' || c > '9') {
    if (c == '-')
      fh = -1;
    c = getchar();
  }
  while (c >= '0' && c <= '9')
    tmp = tmp * 10 + c - 48, c = getchar();
  return tmp * fh;
}
inline int readint() {
  int tmp = 0, fh = 1;
  char c = getchar();
  while (c < '0' || c > '9') {
    if (c == '-')
      fh = -1;
    c = getchar();
  }
  while (c >= '0' && c <= '9')
    tmp = tmp * 10 + c - 48, c = getchar();
  return tmp * fh;
}
void pvarr_int(int *arr, int n, int strat = 1) {
  if (strat == 0) {
    n--;
  }
  repd(i, strat, n) { printf("%d%c", arr[i], i == n ? '\\n' : ' '); }
}
void pvarr_LL(ll *arr, int n, int strat = 1) {
  if (strat == 0) {
    n--;
  }
  repd(i, strat, n) { printf("%lld%c", arr[i], i == n ? '\\n' : ' '); }
}
const int maxn = 500010;
const int inf = 0x3f3f3f3f;
/*** TEMPLATE CODE * * STARTS HERE ***/
#define DEBUG_Switch 0
std::vector<int> v[maxn];
ll n, m;
ll q;
struct node {
  ll id;
  ll val;
  node() {}
  node(ll y, ll v) {
    id = y;
    val = v;
  }
  bool operator<(const node &bb) const {
    if (val != bb.val)
      return val > bb.val;
    else
      return id > bb.id;
  }
};
set<node> st2;
ll cnt_row[maxn];
ll cnt_col[maxn];
int main() {
#if DEBUG_Switch
  freopen("C:\\\\code\\\\input.txt", "r", stdin);
#endif
  // freopen("C:\\\\code\\\\output.txt","w",stdout);
  n = readint();
  m = readint();
  q = readll();
  repd(i, 1, q) {
    int x = readint();
    int y = readint();
    cnt_row[x]++;
    cnt_col[y]++;
    v[x].push_back(y);
  }
  repd(i, 1, m) { st2.insert(node(i, cnt_col[i])); }
  ll ans = 1;
  repd(i, 1, n) {
    ll temp = cnt_row[i];
    for (auto y : v[i]) {
      ans = max(ans, temp + cnt_col[y] - 1);
      st2.erase(st2.lower_bound(node(y, cnt_col[y])));
    }
    auto it = st2.begin();
    if (it == st2.end())
      continue;
    node now = *it;
    ans = max(ans, temp + now.val);
    for (auto y : v[i]) {
      st2.insert(node(y, cnt_col[y]));
    }
  }
  printf("%lld\\n", ans);
  return 0;
}