Submission #866546

#	Time	Username	Problem	Language	Result	Execution time	Memory
866546		nima_aryan	Zoltan (COCI16_zoltan)	C++17	140 / 140	223 ms	18012 KiB

zoltan

/**
 *    author:  NimaAryan
 *    created: 2023-10-26 10:49:24  
**/
#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "algo/debug.h"
#endif

using i64 = long long;

constexpr i64 M = 1E9 + 7;
void add(i64& x, i64 y) {
  if ((x += y) >= M) {
    x -= M;
  }
}

struct Info {
  int max_lis;
  i64 sum = 0;
};
Info operator+(Info a, Info b) {
  if (a.max_lis == b.max_lis) {
    add(a.sum, b.sum);
    return a;
  }
  return a.max_lis > b.max_lis ? a : b;
}

struct SegmentTree {
  vector<Info> info;
  int n;

  SegmentTree(int n) : n(n) {
    info.assign(4 << __lg(n), Info());
  }

  void modify(int p, int l, int r, int x, Info v) {
    if (r - l == 1) {
      info[p] = info[p] + v;
      return;
    }
    int m = (l + r) / 2;
    if (x < m) {
      modify(2 * p, l, m, x, v);
    } else {
      modify(2 * p + 1, m, r, x, v);
    }
    info[p] = info[2 * p] + info[2 * p + 1];
  }
  void modify(int x, Info v) {
    modify(1, 0, n, x, v);
  }

  Info query(int p, int l, int r, int lx, int rx) {
    if (l >= rx || r <= lx) {
      return Info();
    }
    if (l >= lx && r <= rx) {
      return info[p];
    }
    int m = (l + r) / 2;
    return query(2 * p, l, m, lx, rx) +
           query(2 * p + 1, m, r, lx, rx);
  }
  Info query(int lx, int rx) {
    return query(1, 0, n, lx, rx);
  }
};

auto LIS(vector<int> A) {
  auto B = A;
  sort(B.begin(), B.end());
  int n = A.size();
  for (int i = 0; i < n; ++i) {
    A[i] = lower_bound(B.begin(), B.end(), A[i]) - B.begin();
  }
  SegmentTree seg(n + 1);
  seg.modify(n, Info{0, 1});
  vector<int> lis(n);
  vector<i64> cnt(n);
  for (int i = n - 1; i >= 0; --i) {
    Info best = seg.query(A[i] + 1, n + 1);
    lis[i] = best.max_lis + 1;
    cnt[i] = best.sum;
    seg.modify(A[i], Info{lis[i], cnt[i]});
  }
  return pair(lis, cnt);
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int N;
  cin >> N;
  vector<int> A(N);
  for (int i = 0; i < N; ++i) {
    cin >> A[i];
  }
  auto [lis, cnt_lis] = LIS(A);
  for (int i = 0; i < N; ++i) {
    A[i] *= -1;
  }
  auto [lds, cnt_lds] = LIS(A);
  int best = 0;
  for (int i = 0; i < N; ++i) {
    best = max(best, lis[i] + lds[i] - 1);
  }
  i64 pow2 = 1;
  int rem = N - best;
  while (rem > 0) {
    pow2 = (pow2 * 2) % M;
    rem -= 1;
  }
  i64 cnt = 0;
  for (int i = 0; i < N; ++i) {
    if (lis[i] + lds[i] - 1 == best) {
      add(cnt, cnt_lis[i] * cnt_lds[i] % M * pow2 % M);
    }
  }
  cout << best << " " << cnt << "\n";
  return 0;
}

• Subtask 1: 140 / 140