Problem p00090 (C++)

Buggy submission (status: Time Limit Exceeded):
/* template.cpp [[[ */
#include <bits/stdc++.h>
using namespace std;
#define get_macro(a, b, c, d, name, ...) name
#define rep(...) get_macro(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)
#define rrep(...)                                                              \
  get_macro(__VA_ARGS__, rrep4, rrep3, rrep2, rrep1)(__VA_ARGS__)
#define rep1(n) rep2(i_, n)
#define rep2(i, n) rep3(i, 0, n)
#define rep3(i, a, b) rep4(i, a, b, 1)
#define rep4(i, a, b, s) for (ll i = (a); i < (ll)(b); i += (ll)s)
#define rrep1(n) rrep2(i_, n)
#define rrep2(i, n) rrep3(i, 0, n)
#define rrep3(i, a, b) rrep4(i, a, b, 1)
#define rrep4(i, a, b, s) for (ll i = (ll)(b)-1; i >= (ll)(a); i -= (ll)s)
#define each(x, c) for (auto &&x : c)
#define fs first
#define sc second
#define all(c) begin(c), end(c)
using ui = unsigned;
using ll = long long;
using ul = unsigned long long;
using ld = long double;
const int INF = 1e9 + 10;
const ll INF_LL = 1e18 + 10;
const int dx[]{-1, 0, 1, 0, -1, 1, 1, -1};
const int dy[]{0, -1, 0, 1, -1, -1, 1, 1};
template <class T, class U> void chmin(T &x, const U &y) { x = min<T>(x, y); }
template <class T, class U> void chmax(T &x, const U &y) { x = max<T>(x, y); }
/* ]]] */

using P = complex<double>;
const double PI = acos(-1.0);
const double EPS = 1e-6;

int n;
P p[100];

int main() {
  while (cin >> n, n) {
    rep(i, n) {
      double x, y;
      scanf("%lf,%lf", &x, &y);
      p[i] = P(x, y);
    }

    int mx = 0;
    rep(i, n) rep(j, 101) rep(k, 50) {
      P q = p[i] + polar(j * 0.01, k * PI / 50);
      int c = 0;
      rep(l, n) c += abs(p[l] - q) < 1.0 + EPS;
      chmax(mx, c);
    }

    cout << mx << endl;
  }
}

Fixed submission:
/* template.cpp [[[ */
#include <bits/stdc++.h>
using namespace std;
#define get_macro(a, b, c, d, name, ...) name
#define rep(...) get_macro(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)
#define rrep(...)                                                              \
  get_macro(__VA_ARGS__, rrep4, rrep3, rrep2, rrep1)(__VA_ARGS__)
#define rep1(n) rep2(i_, n)
#define rep2(i, n) rep3(i, 0, n)
#define rep3(i, a, b) rep4(i, a, b, 1)
#define rep4(i, a, b, s) for (ll i = (a); i < (ll)(b); i += (ll)s)
#define rrep1(n) rrep2(i_, n)
#define rrep2(i, n) rrep3(i, 0, n)
#define rrep3(i, a, b) rrep4(i, a, b, 1)
#define rrep4(i, a, b, s) for (ll i = (ll)(b)-1; i >= (ll)(a); i -= (ll)s)
#define each(x, c) for (auto &&x : c)
#define fs first
#define sc second
#define all(c) begin(c), end(c)
using ui = unsigned;
using ll = long long;
using ul = unsigned long long;
using ld = long double;
const int INF = 1e9 + 10;
const ll INF_LL = 1e18 + 10;
const int dx[]{-1, 0, 1, 0, -1, 1, 1, -1};
const int dy[]{0, -1, 0, 1, -1, -1, 1, 1};
template <class T, class U> void chmin(T &x, const U &y) { x = min<T>(x, y); }
template <class T, class U> void chmax(T &x, const U &y) { x = max<T>(x, y); }
/* ]]] */

using P = complex<double>;
const double PI = acos(-1.0);
const double EPS = 1e-6;

int n;
P p[100];

int main() {
  while (cin >> n, n) {
    rep(i, n) {
      double x, y;
      scanf("%lf,%lf", &x, &y);
      p[i] = P(x, y);
    }

    int mx = 0;
    rep(i, n) rep(j, 51) rep(k, 50) {
      P q = p[i] + polar(j * 0.02, k * PI / 50);
      int c = 0;
      rep(l, n) c += abs(p[l] - q) < 1.0 + EPS;
      chmax(mx, c);
    }

    cout << mx << endl;
  }
}