Submission #245327

# Submission time Handle Problem Language Result Execution time Memory
245327 2020-07-06T04:04:09 Z neihcr7j Boat (APIO16_boat) C++14
36 / 100
2000 ms 8304 KB
#include<bits/stdc++.h>

#define M 1000000007
#define maxn 502

using namespace std;
typedef long long ll;

inline ll norm(ll a) {
  return (a < 0 ? a + M : (a >= M ? a - M : a));
}

inline ll mul(ll a, ll b) {
  return a * b % M;
}

ll power(ll a, ll b) {
  if (b == 0) return 1;
  if (b&1) return mul(power(a, b - 1), a);
  ll t = power(a, b / 2);
  return mul(t, t);
}

ll gt[maxn * 2], igt[maxn * 2];

void precalc(){
  int n = 1000;

  gt[0] = 1;
  for (int i = 1; i <= n; ++i)
    gt[i] = mul(gt[i - 1], i);

  igt[n] = power(gt[n], M - 2);

  for (int i = n - 1; i >= 0; --i)
    igt[i] = mul(igt[i + 1], i + 1);
}

ll C(int n, int k) {
  return mul(mul(gt[n], igt[k]), igt[n - k]);
}


int n;

int l[maxn], r[maxn];
vector < pair < int, int > > seg;
vector < vector < int > > a;
vector < int > leng;

ll dp[maxn * 4][maxn];

int main(){
  #define TASK "ABC"
 // freopen(TASK".inp", "r", stdin); freopen(TASK".out", "w", stdout);
  ios_base::sync_with_stdio(0);

  precalc();

  cin >> n;

  vector < int > ret;

  for (int i = 1; i <= n; ++i) {
    cin >> l[i] >> r[i];

    ret.push_back(l[i]);
    ret.push_back(r[i]);
  }

  sort(ret.begin(), ret.end());

  seg.push_back({ret[0], ret[0]});

  for (int i = 1; i < ret.size(); ++i)
    if (ret[i] != ret[i - 1]) {
    //  if (i == ret.size() || ret[i] != ret[i + 1]) {
    //    seg.push_back({ret[i - 1] + 1, ret[i]});
    //    continue;
    //  }

      if (ret[i - 1] + 1 != ret[i])
        seg.push_back({ret[i - 1] + 1, ret[i] - 1});
      seg.push_back({ret[i], ret[i]});
    }

  a = vector < vector < int > >(seg.size(), vector < int >(0, 0));
  leng = vector < int > (seg.size(), 0);

  for (int i = 0; i < seg.size(); ++i) {
    for (int j = 1; j <= n; ++j)
      if (l[j] <= seg[i].first && seg[i].second <= r[j])
        a[i].push_back(j);
    leng[i] = seg[i].second - seg[i].first + 1;
  }

  ll ans = 0;

  if (seg.size() > 2000) exit(-1);

  for (int i = 0; i < seg.size(); ++i) {
    ll l = leng[i];

    vector < ll > c(a[i].size() + 1, 0), val(a[i].size() + 1, 0);

    c[0] = 1;

    for (int k = 1; k <= a[i].size(); ++k) {
      if (k <= l)
        c[k] = mul(mul(c[k - 1], l - k + 1), power(k, M - 2));

      for (int x = k; x > 0; --x)
        if (x <= l)
          val[k] = norm(val[k] + mul(c[x], C(k - 1, x - 1)));
    }

     int index = 0;

    for (int k = 0; k <= n; ++k) {
      ll res = (k == 0 ? 1 : 0);

      for (int j = 0; j < i; ++j)
        res = norm(res + dp[j][k]);

      while (index < a[i].size() && a[i][index] <= k)
        index++;

      for (int j = index; j < a[i].size(); ++j)
        dp[i][a[i][j]] = norm(dp[i][a[i][j]] + mul(res, val[j - index + 1]));

      ans = norm(ans + dp[i][k]);
    }
  }

  cout << ans;

  return 0;
}

Compilation message

boat.cpp: In function 'int main()':
boat.cpp:75:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 1; i < ret.size(); ++i)
                   ~~^~~~~~~~~~~~
boat.cpp:90:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 0; i < seg.size(); ++i) {
                   ~~^~~~~~~~~~~~
boat.cpp:101:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 0; i < seg.size(); ++i) {
                   ~~^~~~~~~~~~~~
boat.cpp:108:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int k = 1; k <= a[i].size(); ++k) {
                     ~~^~~~~~~~~~~~~~
boat.cpp:125:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       while (index < a[i].size() && a[i][index] <= k)
              ~~~~~~^~~~~~~~~~~~~
boat.cpp:128:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       for (int j = index; j < a[i].size(); ++j)
                           ~~^~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 433 ms 2424 KB Output is correct
2 Correct 433 ms 2424 KB Output is correct
3 Correct 431 ms 2424 KB Output is correct
4 Correct 450 ms 2460 KB Output is correct
5 Correct 432 ms 2400 KB Output is correct
6 Correct 440 ms 2552 KB Output is correct
7 Correct 425 ms 2552 KB Output is correct
8 Correct 464 ms 2428 KB Output is correct
9 Correct 436 ms 2424 KB Output is correct
10 Correct 428 ms 2424 KB Output is correct
11 Correct 434 ms 2424 KB Output is correct
12 Correct 435 ms 2424 KB Output is correct
13 Correct 437 ms 2424 KB Output is correct
14 Correct 425 ms 2424 KB Output is correct
15 Correct 449 ms 2552 KB Output is correct
16 Correct 19 ms 896 KB Output is correct
17 Correct 21 ms 896 KB Output is correct
18 Correct 21 ms 896 KB Output is correct
19 Correct 22 ms 1024 KB Output is correct
20 Correct 20 ms 1024 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 433 ms 2424 KB Output is correct
2 Correct 433 ms 2424 KB Output is correct
3 Correct 431 ms 2424 KB Output is correct
4 Correct 450 ms 2460 KB Output is correct
5 Correct 432 ms 2400 KB Output is correct
6 Correct 440 ms 2552 KB Output is correct
7 Correct 425 ms 2552 KB Output is correct
8 Correct 464 ms 2428 KB Output is correct
9 Correct 436 ms 2424 KB Output is correct
10 Correct 428 ms 2424 KB Output is correct
11 Correct 434 ms 2424 KB Output is correct
12 Correct 435 ms 2424 KB Output is correct
13 Correct 437 ms 2424 KB Output is correct
14 Correct 425 ms 2424 KB Output is correct
15 Correct 449 ms 2552 KB Output is correct
16 Correct 19 ms 896 KB Output is correct
17 Correct 21 ms 896 KB Output is correct
18 Correct 21 ms 896 KB Output is correct
19 Correct 22 ms 1024 KB Output is correct
20 Correct 20 ms 1024 KB Output is correct
21 Execution timed out 2082 ms 8304 KB Time limit exceeded
22 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 26 ms 2040 KB Output is correct
2 Correct 25 ms 2048 KB Output is correct
3 Correct 25 ms 2048 KB Output is correct
4 Correct 28 ms 2040 KB Output is correct
5 Correct 26 ms 2048 KB Output is correct
6 Correct 30 ms 2048 KB Output is correct
7 Correct 30 ms 2048 KB Output is correct
8 Correct 30 ms 2048 KB Output is correct
9 Correct 30 ms 2048 KB Output is correct
10 Correct 31 ms 2044 KB Output is correct
11 Correct 28 ms 2040 KB Output is correct
12 Correct 25 ms 2048 KB Output is correct
13 Correct 25 ms 2040 KB Output is correct
14 Correct 26 ms 2048 KB Output is correct
15 Correct 26 ms 2048 KB Output is correct
16 Correct 10 ms 1024 KB Output is correct
17 Correct 10 ms 1024 KB Output is correct
18 Correct 10 ms 1024 KB Output is correct
19 Correct 10 ms 1152 KB Output is correct
20 Correct 11 ms 1076 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 433 ms 2424 KB Output is correct
2 Correct 433 ms 2424 KB Output is correct
3 Correct 431 ms 2424 KB Output is correct
4 Correct 450 ms 2460 KB Output is correct
5 Correct 432 ms 2400 KB Output is correct
6 Correct 440 ms 2552 KB Output is correct
7 Correct 425 ms 2552 KB Output is correct
8 Correct 464 ms 2428 KB Output is correct
9 Correct 436 ms 2424 KB Output is correct
10 Correct 428 ms 2424 KB Output is correct
11 Correct 434 ms 2424 KB Output is correct
12 Correct 435 ms 2424 KB Output is correct
13 Correct 437 ms 2424 KB Output is correct
14 Correct 425 ms 2424 KB Output is correct
15 Correct 449 ms 2552 KB Output is correct
16 Correct 19 ms 896 KB Output is correct
17 Correct 21 ms 896 KB Output is correct
18 Correct 21 ms 896 KB Output is correct
19 Correct 22 ms 1024 KB Output is correct
20 Correct 20 ms 1024 KB Output is correct
21 Execution timed out 2082 ms 8304 KB Time limit exceeded
22 Halted 0 ms 0 KB -