Submission #946201

#	Time	Username	Problem	Language	Result	Execution time	Memory
946201		RedGrey1993	Sailing Race (CEOI12_race)	C++17	100 / 100	846 ms	5764 KiB

race

#include <bits/stdc++.h>
 
using namespace std;
 
template <typename T1, typename T2> istream &operator>>(istream &is, pair<T1, T2> &pa) { is >> pa.first >> pa.second; return is; }
template <typename T> istream &operator>>(istream &is, vector<T> &vec) { for (auto &v : vec) is >> v; return is; }
template <typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &pa) { os << "(" << pa.first << "," << pa.second << ")"; return os; }
template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) { os << "["; for (auto v : vec) os << v << ","; os << "]"; return os; }
template <typename T> ostream &operator<<(ostream &os, const deque<T> &vec) { os << "deq["; for (auto v : vec) os << v << ","; os << "]"; return os; }
template <typename T> ostream &operator<<(ostream &os, const set<T> &vec) { os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &vec) { os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template <typename T> ostream &operator<<(ostream &os, const unordered_set<T> &vec) { os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template <typename T> ostream &operator<<(ostream &os, const unordered_multiset<T> &vec) { os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template <typename TK, typename TV> ostream &operator<<(ostream &os, const unordered_map<TK, TV> &mp) { os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; }
template <typename TK, typename TV> ostream &operator<<(ostream &os, const map<TK, TV> &mp) { os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; }
template <typename T> void resize_array(vector<T> &vec, int len) { vec.resize(len); }
template <typename T, typename... Args> void resize_array(vector<T> &vec, int len, Args... args) { vec.resize(len); for (auto &v : vec) resize_array(v, args...); }
template <typename T1, typename T2> pair<T1, T2> operator+(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first + r.first, l.second + r.second); }
template <typename T1, typename T2> pair<T1, T2> operator-(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first - r.first, l.second - r.second); }
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
mt19937 mrand(random_device{}());
int rnd(int x) { return mrand() % x; }
 
template <unsigned int MOD>
class ModInt {
public:
    ModInt(unsigned long long _v = 0) { set_v((_v % MOD + MOD)); }
    explicit operator bool() const { return val != 0; }
    ModInt operator-() const { return ModInt() - *this; }
    ModInt operator+(const ModInt &r) const { return ModInt().set_v(val + r.val); }
    ModInt operator-(const ModInt &r) const { return ModInt().set_v(val + MOD - r.val); }
    ModInt operator*(const ModInt &r) const { return ModInt().set_v((unsigned int)((unsigned long long)(val)*r.val % MOD)); }
    ModInt operator/(const ModInt &r) const { return *this * r.inv(); }
    ModInt &operator+=(const ModInt &r) { return *this = *this + r; }
    ModInt &operator-=(const ModInt &r) { return *this = *this - r; }
    ModInt &operator*=(const ModInt &r) { return *this = *this * r; }
    ModInt &operator/=(const ModInt &r) { return *this = *this / r; }
    // ModInt &operator=(unsigned long long _v) { set_v((_v % MOD + MOD)); return *this; }
    unsigned int operator=(unsigned long long _v) { set_v((_v % MOD + MOD)); return val; }
    bool operator==(const ModInt &r) const { return val == r.val; }
    bool operator!=(const ModInt &r) const { return val != r.val; }
    ModInt pow(long long n) const {
        ModInt x = *this, r = 1;
        while (n) {
            if (n & 1)
                r *= x;
            x *= x;
            n >>= 1;
        }
        return r;
    }
    ModInt inv() const { return pow(MOD - 2); }
    unsigned int get_val() { return val; }
    friend ostream &operator<<(ostream &os, const ModInt &r) { return os << r.val; }
    friend istream &operator>>(istream &is, ModInt &r) { return is >> r.val; }
private:
    unsigned int val;
    ModInt &set_v(unsigned int _v) {
        val = (_v < MOD) ? _v : _v - MOD;
        return *this;
    }
};
constexpr unsigned int mod = 1e9+7;
using Mint = ModInt<mod>;
 
#define rep(i, a, n) for (int i = a; i < (n); i++)
#define per(i, a, n) for (int i = (n)-1; i >= a; i--)
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(), (x).end()
#define fi first
#define se second
#define sz(x) ((int)(x).size())
typedef vector<int> vi;
typedef long long ll;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef double db;
#if DEBUG
#define dbg(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ") " << __FILE__ << endl;
#else
#define dbg(x)
#endif
 
using Mint2 = ModInt<mod-1>;

template <typename T>
struct Line {
  T k, b;
  // 集合中的直线按照斜率从小到大排序，该值表示本直线与下一条直线的交点的横坐标
  mutable T intersect_x;
  bool operator<(const Line<T>& o) const {
    return k < o.k;
  }                            // 用于按照斜率排序
  bool operator<(T x) const {  // 用于在Query时进行二分查找
    return intersect_x < x;
  }                                        // 用于二分查找
  T Eval(T x) const { return k * x + b; }  // 求直线在x点的y值
  T IntersectX(const Line<T>& line) const {  // 求与直线line的交点的横坐标
    assert(k != line.k);  // 斜率不能相等，否则除0异常
    return Div(line.b - b, k - line.k);
  }
  T Div(T a, T b) const {
    if constexpr (std::is_integral<T>::value) {
      // floored division,
      // 因为两条直线之间的交点可能是小数，但是x是整数，因此小数部分永远不会取到
      // 所以求直线交点时只需要记录<=交点横坐标值的最大整数即可
      // 3/2 -> 1; -3/2 -> -2; 4/2 -> 2; -4/2 -> 2
      return a / b - ((a ^ b) < 0 && a % b);
    } else {
      return a / b;
    }
  }
};

template <typename T>
class LichaoTree {
  struct Node {
    Line<T> line{0, numeric_limits<T>::max()};
    int left = -1, right = -1;
  };
 public:
  LichaoTree(T mint, T maxt) {
    mint_ = mint;
    maxt_ = maxt;
  }
  void Add(const Line<T>& line) {
    Add(line, root_, mint_, maxt_);
  }

  T Query(T x) {
    return Query(x, 0, mint_, maxt_);
  }

 private:
  void Add(Line<T> line, int& v, T l, T r) {
    if (v == -1) {
        v = trees.size();
        trees.emplace_back(Node{line, -1, -1});
        return;
    }
    T m = l + (r - l) / 2;
    bool lef = line.Eval(l) < trees[v].line.Eval(l);
    bool mid = line.Eval(m) < trees[v].line.Eval(m);
    bool rht = line.Eval(r) < trees[v].line.Eval(r);
    if (mid) {
      swap(trees[v].line, line);
    }
    if ((lef && rht) || (!lef && !rht)) {
      return;
    } else if (lef != mid) {
      Add(line, trees[v].left, l, m);
    } else {
      Add(line, trees[v].right, m, r);
    }
  }
  T Query(T x, int v, T l, T r) {
    if (v == -1) return numeric_limits<T>::max();
    T m = l + (r - l) / 2;
    if (x < m) {
      return min(trees[v].line.Eval(x), Query(x, trees[v].left, l, m));
    } else {
      return min(trees[v].line.Eval(x), Query(x, trees[v].right, m, r));
    }
  }
  T mint_,maxt_;
  vector<Node> trees;
  int root_ = -1;
};

class Solution {
public:
    void Solve() {
        int n,op;
        while(cin>>n>>op) {
            vector<vi> edges(n+1);
            vector<vi> has_edge(n+1, vi(n+1, 0));
            rep(from,1,n+1) {
                int to;
                while(cin>>to) {
                    if (to == 0) break;
                    edges[from].emplace_back(to);
                    has_edge[from][to] = 1;
                }
            }
            // c -> clockwise, cc -> counter_clockwise
            vector<vi> dp_c(n+1, vi(n+1, -1)), dp_cc(n+1, vi(n+1, -1));
            // is s<k<e ?
            auto between_range = [&] (int k, int s, int e, bool clockwise) {
                if (clockwise) swap(s, e);
                if (s==e) return k!=s;
                int d1 = k-s; if (d1<0) d1 += n;
                int d2 = e-s; if (d2<0) d2 += n;
                return k!=s && d1 < d2;
            };

            function<int(int,int)> dfs_c,dfs_cc;
            // [i,j)
            // dp_c[i][j] = 1 + max(dp_c[k][j], dp_cc[k][i])  exists(i->k, j<k<i)
            // dp_cc[i][j] = 1 + max(dp_cc[k][j], dp_c[k][i]) exists(i->k, i<k<j)
            dfs_c = [&] (int i, int j) -> int {
                if (dp_c[i][j] != -1) return dp_c[i][j];
                dp_c[i][j] = 0;
                for (int k : edges[i]) {
                    if (between_range(k, i, j, true)) {
                        dp_c[i][j] = max(dp_c[i][j], 1 + max(dfs_c(k, j), dfs_cc(k, i)));
                    }
                }
                return dp_c[i][j];
            };

            dfs_cc = [&] (int i, int j) -> int {
                if (dp_cc[i][j] != -1) return dp_cc[i][j];
                dp_cc[i][j] = 0;
                for (int k : edges[i]) {
                    if (between_range(k, i, j, false)) {
                        dp_cc[i][j] = max(dp_cc[i][j], 1 + max(dfs_cc(k, j), dfs_c(k, i)));
                    }
                }
                return dp_cc[i][j];
            };

            int ans = 0, st = 0;
            rep(i,1,n+1) {
              rep(j,1,n+1) {
                if (dfs_c(i, j) > ans) {
                  ans = dfs_c(i, j);
                  st = i;
                }
                if (dfs_cc(i, j) > ans) {
                  ans = dfs_cc(i, j);
                  st = i;
                }
              }
            }
            // dbg(dp_c);
            // dbg(dp_cc);

            if (op) {
              vector<vi> dp_succ_c(n+1, vi(n+1, -1)), dp_succ_cc(n+1, vi(n+1, -1));
              function<int(int,int)> dfs_succ_c = [&] (int i, int j) -> int {
                  if (i==j) return dp_succ_c[i][j]=0;
                  if (dp_succ_c[i][j] != -1) return dp_succ_c[i][j];
                  dp_succ_c[i][j] = -2;
                  for (int k : edges[i]) {
                      if ((k==j||between_range(k, i, j, true)) && dfs_succ_c(k, j) >= 0) {
                          dp_succ_c[i][j] = max(dp_succ_c[i][j], 1 + dfs_succ_c(k, j));
                      }
                  }
                  return dp_succ_c[i][j];
              };
              rep(i,1,n+1) {
                rep(j,1,n+1) dfs_succ_c(i,j);
              }

              function<int(int,int)> dfs_succ_cc = [&] (int i, int j) -> int {
                  if (i==j) return dp_succ_cc[i][j]=0;
                  if (dp_succ_cc[i][j] != -1) return dp_succ_cc[i][j];
                  dp_succ_cc[i][j] = -2;
                  for (int k : edges[i]) {
                      if ((k==j||between_range(k, i, j, false)) && dfs_succ_cc(k, j) >= 0) {
                          dp_succ_cc[i][j] = max(dp_succ_cc[i][j], 1 + dfs_succ_cc(k, j));
                      }
                  }
                  return dp_succ_cc[i][j];
              };
              rep(i,1,n+1) {
                rep(j,1,n+1) dfs_succ_cc(i,j);
              }
              // dbg(dp_succ_c);
              // dbg(dp_succ_cc);

              vi ansv(n+1);
              // ans[i] = max(1+dp_succ_c[j][k]+1+max(dp_c[l][j], dp_cc[l][i])) exists(k->l, j<l<i), dp_succ_c[j][k]!=0
              rep(j,1,n+1) {
                int i = j + 1, k = i + 1;
                if (i > n) i -= n; if (k > n) k-=n;
                while(true) {
                  if (has_edge[i][j]) {
                    if (dp_succ_c[j][k] > 0) {
                      for (int l:edges[k]) {
                        if (between_range(l,i,j,true)) ansv[i] = max(ansv[i], 1+dp_succ_c[j][k]+1+max(dp_c[l][j], dp_cc[l][i]));
                      }
                    }
                    if (has_edge[k][j]) i = k;
                    k++; if (k > n) k-=n;
                  } else {
                    i++; k=i+1;
                    if (i > n) i -= n; if (k > n) k-=n;
                  }
                  if (k==j) break;
                  if (i==j) break;
                }
              }

              // ans[i] = max(1+dp_succ_cc[j][k]+1+max(dp_cc[l][j], dp_c[l][i])) exists(k->l, i<l<j), dp_succ_cc[j][k]!=0
              rep(j,1,n+1) {
                int i = j - 1, k = i - 1;
                if (i < 1) i += n; if (k < 1) k+=n;
                while(true) {
                  if (has_edge[i][j]) {
                    if (dp_succ_cc[j][k] > 0) {
                      for (int l:edges[k]) {
                        if (between_range(l,i,j,false)) ansv[i] = max(ansv[i], 1+dp_succ_cc[j][k]+1+max(dp_cc[l][j], dp_c[l][i]));
                      }
                    }
                    if (has_edge[k][j]) i = k;
                    k--; if (k < 1) k+=n;
                  } else {
                    i--; k=i-1;
                    if (i < 1) i += n; if (k < 1) k+=n;
                  }
                  if (k==j) break;
                  if (i==j) break;
                }
              }

              // dbg(ansv);
              // ans = 0; st = 0;
              rep(i,1,n+1) if (ansv[i]>ans) {
                ans = ansv[i];
                st = i;
              }
            }

            cout << ans << endl;
            cout << st << endl;
        }
    }
private:
};
 
// #define USACO 1
void set_io(const string &name = "") {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
#if FILE_IO || USACO
    if (!name.empty()) {
        freopen((name + ".in").c_str(), "r", stdin);
        freopen((name + ".out").c_str(), "w", stdout);
    }
#endif
}

int main() {
#if USACO
    set_io("time");
#else
    set_io("tmp");
#endif
    Solution().Solve();

    return 0;
}

Compilation message (stderr)

race.cpp: In member function 'void Solution::Solve()':
race.cpp:278:17: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  278 |                 if (i > n) i -= n; if (k > n) k-=n;
      |                 ^~
race.cpp:278:36: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  278 |                 if (i > n) i -= n; if (k > n) k-=n;
      |                                    ^~
race.cpp:290:21: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  290 |                     if (i > n) i -= n; if (k > n) k-=n;
      |                     ^~
race.cpp:290:40: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  290 |                     if (i > n) i -= n; if (k > n) k-=n;
      |                                        ^~
race.cpp:300:17: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  300 |                 if (i < 1) i += n; if (k < 1) k+=n;
      |                 ^~
race.cpp:300:36: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  300 |                 if (i < 1) i += n; if (k < 1) k+=n;
      |                                    ^~
race.cpp:312:21: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  312 |                     if (i < 1) i += n; if (k < 1) k+=n;
      |                     ^~
race.cpp:312:40: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  312 |                     if (i < 1) i += n; if (k < 1) k+=n;
      |                                        ^~

• Subtask 1: 100 / 100