Problem p01350 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <algorithm>
#include <bitset>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <valarray>
#include <vector>
using namespace std;
typedef long long int ll;
typedef unsigned int uint;
typedef unsigned char uchar;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;

#define REP(i, x) for (int i = 0; i < (int)(x); i++)
#define REPS(i, x) for (int i = 1; i <= (int)(x); i++)
#define RREP(i, x) for (int i = ((int)(x)-1); i >= 0; i--)
#define RREPS(i, x) for (int i = ((int)(x)); i > 0; i--)
#define FOR(i, c)                                                              \\
  for (__typeof((c).begin()) i = (c).begin(); i != (c).end(); i++)
#define RFOR(i, c)                                                             \\
  for (__typeof((c).rbegin()) i = (c).rbegin(); i != (c).rend(); i++)
#define ALL(container) (container).begin(), (container).end()
#define RALL(container) (container).rbegin(), (container).rend()
#define SZ(container) ((int)container.size())
#define mp(a, b) make_pair(a, b)
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end());

template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> ostream &operator<<(ostream &os, const vector<T> &t) {
  os << "[";
  FOR(it, t) {
    if (it != t.begin())
      os << ",";
    os << *it;
  }
  os << "]";
  return os;
}
template <class T> ostream &operator<<(ostream &os, const set<T> &t) {
  os << "{";
  FOR(it, t) {
    if (it != t.begin())
      os << ",";
    os << *it;
  }
  os << "}";
  return os;
}
template <class S, class T>
ostream &operator<<(ostream &os, const pair<S, T> &t) {
  return os << "(" << t.first << "," << t.second << ")";
}
template <class S, class T>
pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) {
  return pair<S, T>(s.first + t.first, s.second + t.second);
}
template <class S, class T>
pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) {
  return pair<S, T>(s.first - t.first, s.second - t.second);
}

const int INF = 1 << 28;
const double EPS = 1e-8;
const int MOD = 1000000007;

typedef double R;
typedef complex<R> P;
const R PI = 3.1415926535897932384626;

istream &operator>>(istream &is, P &p) {
  R x, y;
  is >> x >> y;
  p = P(x, y);
  return is;
}

int n;
double r, theta;

double visited[401][10005];

int main() {
  ios::sync_with_stdio(false);
  cin >> n >> r >> theta;
  theta = theta / 180. * PI;
  vector<P> p(n);
  REP(i, n) cin >> p[i];
  vector<vector<pair<int, double>>> g(n * n);
  REP(i, n) REP(j, n) REP(k, n) {
    if (i == k || i == j || j == k)
      continue;
    if (abs(arg((p[j] - p[i]) / (p[k] - p[j]))) < theta) {
      g[j * n + i].emplace_back(k * n + j, abs(p[k] - p[j]));
    }
  }
  struct State {
    int x, c;
    double cost;
    State(int x, int c, double cost) : x(x), c(c), cost(cost) {}
    bool operator<(const State &opp) const { return cost > opp.cost; }
  };
  priority_queue<State> que;
  REP(i, 1) REP(j, n) if (i != j) {
    if (abs(p[i] - p[j]) < r) {
      que.emplace(j * n + i, 1, abs(p[i] - p[j]));
      visited[j * n + i][1] = abs(p[i] - p[j]);
    }
  }
  int ans = 0;
  while (!que.empty()) {
    const State s = que.top();
    que.pop();
    if (s.cost > visited[s.x][s.c])
      continue;
    ans = max(ans, s.c);
    FOR(it, g[s.x]) {
      int x = it->first;
      double cost = s.cost + it->second;
      int c = s.c + 1;
      auto &t = visited[x][c];
      if ((t == 0 || cost < t) && cost < r) {
        t = cost;
        que.emplace(x, c, cost);
      }
    }
  }
  cout << ans << endl;
  return 0;
}

Error: TLE

Fixed submission:

#include <algorithm>
#include <bitset>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <valarray>
#include <vector>
using namespace std;
typedef long long int ll;
typedef unsigned int uint;
typedef unsigned char uchar;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;

#define REP(i, x) for (int i = 0; i < (int)(x); i++)
#define REPS(i, x) for (int i = 1; i <= (int)(x); i++)
#define RREP(i, x) for (int i = ((int)(x)-1); i >= 0; i--)
#define RREPS(i, x) for (int i = ((int)(x)); i > 0; i--)
#define FOR(i, c)                                                              \\
  for (__typeof((c).begin()) i = (c).begin(); i != (c).end(); i++)
#define RFOR(i, c)                                                             \\
  for (__typeof((c).rbegin()) i = (c).rbegin(); i != (c).rend(); i++)
#define ALL(container) (container).begin(), (container).end()
#define RALL(container) (container).rbegin(), (container).rend()
#define SZ(container) ((int)container.size())
#define mp(a, b) make_pair(a, b)
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end());

template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> ostream &operator<<(ostream &os, const vector<T> &t) {
  os << "[";
  FOR(it, t) {
    if (it != t.begin())
      os << ",";
    os << *it;
  }
  os << "]";
  return os;
}
template <class T> ostream &operator<<(ostream &os, const set<T> &t) {
  os << "{";
  FOR(it, t) {
    if (it != t.begin())
      os << ",";
    os << *it;
  }
  os << "}";
  return os;
}
template <class S, class T>
ostream &operator<<(ostream &os, const pair<S, T> &t) {
  return os << "(" << t.first << "," << t.second << ")";
}
template <class S, class T>
pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) {
  return pair<S, T>(s.first + t.first, s.second + t.second);
}
template <class S, class T>
pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) {
  return pair<S, T>(s.first - t.first, s.second - t.second);
}

const int INF = 1 << 28;
const double EPS = 1e-8;
const int MOD = 1000000007;

typedef double R;
typedef complex<R> P;
const R PI = 3.1415926535897932384626;

istream &operator>>(istream &is, P &p) {
  R x, y;
  is >> x >> y;
  p = P(x, y);
  return is;
}

int n;
double r, theta;

double visited[401][10005];

int main() {
  ios::sync_with_stdio(false);
  cin >> n >> r >> theta;
  theta = theta / 180. * PI;
  vector<P> p(n);
  REP(i, n) cin >> p[i];
  vector<vector<pair<int, double>>> g(n * n);
  REP(i, n) REP(j, n) REP(k, n) {
    if (i == k || i == j || j == k)
      continue;
    if (abs(arg((p[j] - p[i]) / (p[k] - p[j]))) < theta)
      g[j * n + i].emplace_back(k * n + j, abs(p[k] - p[j]));
  }
  struct State {
    int x, c;
    double cost;
    State(int x, int c, double cost) : x(x), c(c), cost(cost) {}
    bool operator<(const State &opp) const { return cost < opp.cost; }
  };
  priority_queue<State> que;
  REP(i, n) REP(j, n) if (i != j) {
    if (abs(p[i] - p[j]) < r) {
      que.emplace(j * n + i, 1, abs(p[i] - p[j]));
      visited[j * n + i][1] = abs(p[i] - p[j]);
    }
  }
  int ans = 0;
  while (!que.empty()) {
    State s = que.top();
    que.pop();
    if (s.cost > visited[s.x][s.c])
      continue;
    ans = max(ans, s.c);
    FOR(it, g[s.x]) {
      int x = it->first;
      double cost = s.cost + it->second;
      int c = s.c + 1;
      auto &t = visited[x][c];
      if ((t == 0 || t > cost) && cost < r) {
        t = cost;
        que.emplace(x, c, cost);
      }
    }
  }
  cout << ans << endl;
  return 0;
}