Problem p02580 (C++)

Buggy submission (status: Time Limit Exceeded):

/**
 * Dont raise your voice, improve your argument.
 * --Desmond Tutu
 */

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

const bool ready = []() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout << fixed << setprecision(12);
  return true;
}();

const double PI = acos(-1);
using ll = long long;
#define int ll
#define all(v) (v).begin(), (v).end()
#define fori(n) for (int i = 0; i < int(n); i++)

#define cini(i)                                                                \
  int i;                                                                       \
  cin >> i;
#define cins(s)                                                                \
  string s;                                                                    \
  cin >> s;
#define cind(d)                                                                \
  double d;                                                                    \
  cin >> d;
#define cinai(a, n)                                                            \
  vi a(n);                                                                     \
  fori(n) { cin >> a[i]; }
#define cinas(s, n)                                                            \
  vs s(n);                                                                     \
  fori(n) { cin >> s[i]; }
#define cinad(a, n)                                                            \
  vd a(n);                                                                     \
  fori(n) { cin >> a[i]; }

using pii = pair<int, int>;
using pdd = pair<double, double>;
using vd = vector<double>;
using vb = vector<bool>;
using vi = vector<int>;
using vvi = vector<vi>;
using vs = vector<string>;

#define endl "\n"

/* we want to find the
 * row+col with most targets in it
 * Somehow we need to
 * recognize double count the crossing.
 */
void solve() {
  cini(h);
  cini(w);
  cini(m);

  vector<pii> hcnt(h);
  for (int i = 0; i < h; i++)
    hcnt[i].second = i;
  vector<pii> wcnt(w);
  for (int j = 0; j < w; j++)
    wcnt[j].second = j;

  map<pii, int> s;
  for (int i = 0; i < m; i++) {
    cini(th);
    cini(tw);
    th--;
    tw--;
    s[{th, tw}]++;
    hcnt[th].first++;
    wcnt[tw].first++;
  }
  sort(all(hcnt), greater<pii>());
  sort(all(wcnt), greater<pii>());

  int ans = 0;
  for (int i = 0; i < h; i++) {
    if (hcnt[i].first < hcnt[0].first)
      break;

    for (int j = 0; j < w; j++) {
      if (wcnt[j].first < wcnt[0].first)
        break;

      int lans = hcnt[i].first + wcnt[j].first;
      ans = max(ans, lans - s[{hcnt[i].second, wcnt[j].second}]);
    }
  }
  cout << ans << endl;
}

signed main() { solve(); }

// FIRST THINK, THEN CODE
// DO NOT JUMP BETWEEN PROBLEMS


Fixed submission:

/**
 * Dont raise your voice, improve your argument.
 * --Desmond Tutu
 */

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

const bool ready = []() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout << fixed << setprecision(12);
  return true;
}();

const double PI = acos(-1);
using ll = long long;
#define int ll
#define all(v) (v).begin(), (v).end()
#define fori(n) for (int i = 0; i < int(n); i++)

#define cini(i)                                                                \
  int i;                                                                       \
  cin >> i;
#define cins(s)                                                                \
  string s;                                                                    \
  cin >> s;
#define cind(d)                                                                \
  double d;                                                                    \
  cin >> d;
#define cinai(a, n)                                                            \
  vi a(n);                                                                     \
  fori(n) { cin >> a[i]; }
#define cinas(s, n)                                                            \
  vs s(n);                                                                     \
  fori(n) { cin >> s[i]; }
#define cinad(a, n)                                                            \
  vd a(n);                                                                     \
  fori(n) { cin >> a[i]; }

using pii = pair<int, int>;
using pdd = pair<double, double>;
using vd = vector<double>;
using vb = vector<bool>;
using vi = vector<int>;
using vvi = vector<vi>;
using vs = vector<string>;

#define endl "\n"

/* we want to find the
 * row+col with most targets in it
 * Somehow we need to
 * recognize double count the crossing.
 */
void solve() {
  cini(h);
  cini(w);
  cini(m);

  vector<pii> hcnt(h);
  for (int i = 0; i < h; i++)
    hcnt[i].second = i;
  vector<pii> wcnt(w);
  for (int j = 0; j < w; j++)
    wcnt[j].second = j;

  map<pii, int> s;
  for (int i = 0; i < m; i++) {
    cini(th);
    cini(tw);
    th--;
    tw--;
    s[{th, tw}]++;
    hcnt[th].first++;
    wcnt[tw].first++;
  }
  sort(all(hcnt), greater<pii>());
  sort(all(wcnt), greater<pii>());

  int ans = 0;
  for (int i = 0; i < h; i++) {
    if (hcnt[i].first < hcnt[0].first)
      break;

    for (int j = 0; j < w; j++) {
      if (wcnt[j].first < wcnt[0].first)
        break;

      int lans = hcnt[i].first + wcnt[j].first;
      int dec = s[{hcnt[i].second, wcnt[j].second}];
      ans = max(ans, lans - dec);
      if (dec == 0)
        break;
    }
  }
  cout << ans << endl;
}

signed main() { solve(); }

// FIRST THINK, THEN CODE
// DO NOT JUMP BETWEEN PROBLEMS