oj.uz

Submission #245321

# Submission time Handle Problem Language Result Execution time Memory
245321 2020-07-06T03:57:19 Z neihcr7j Boat (APIO16_boat) C++14
36 / 100
 2000 ms 8064 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 (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;

  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:85:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 0; i < seg.size(); ++i) {
                   ~~^~~~~~~~~~~~
boat.cpp:94:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 0; i < seg.size(); ++i) {
                   ~~^~~~~~~~~~~~
boat.cpp:101:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int k = 1; k <= a[i].size(); ++k) {
                     ~~^~~~~~~~~~~~~~
boat.cpp:118:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       while (index < a[i].size() && a[i][index] <= k)
              ~~~~~~^~~~~~~~~~~~~
boat.cpp:121:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       for (int j = index; j < a[i].size(); ++j)
                           ~~^~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 428 ms 2424 KB Output is correct
2 Correct 427 ms 2424 KB Output is correct
3 Correct 446 ms 2552 KB Output is correct
4 Correct 438 ms 2424 KB Output is correct
5 Correct 449 ms 2424 KB Output is correct
6 Correct 439 ms 2424 KB Output is correct
7 Correct 439 ms 2424 KB Output is correct
8 Correct 424 ms 2424 KB Output is correct
9 Correct 461 ms 2424 KB Output is correct
10 Correct 427 ms 2504 KB Output is correct
11 Correct 429 ms 2460 KB Output is correct
12 Correct 435 ms 2424 KB Output is correct
13 Correct 429 ms 2364 KB Output is correct
14 Correct 429 ms 2424 KB Output is correct
15 Correct 425 ms 2424 KB Output is correct
16 Correct 19 ms 896 KB Output is correct
17 Correct 22 ms 1024 KB Output is correct
18 Correct 23 ms 1024 KB Output is correct
19 Correct 21 ms 1024 KB Output is correct
20 Correct 22 ms 896 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 428 ms 2424 KB Output is correct
2 Correct 427 ms 2424 KB Output is correct
3 Correct 446 ms 2552 KB Output is correct
4 Correct 438 ms 2424 KB Output is correct
5 Correct 449 ms 2424 KB Output is correct
6 Correct 439 ms 2424 KB Output is correct
7 Correct 439 ms 2424 KB Output is correct
8 Correct 424 ms 2424 KB Output is correct
9 Correct 461 ms 2424 KB Output is correct
10 Correct 427 ms 2504 KB Output is correct
11 Correct 429 ms 2460 KB Output is correct
12 Correct 435 ms 2424 KB Output is correct
13 Correct 429 ms 2364 KB Output is correct
14 Correct 429 ms 2424 KB Output is correct
15 Correct 425 ms 2424 KB Output is correct
16 Correct 19 ms 896 KB Output is correct
17 Correct 22 ms 1024 KB Output is correct
18 Correct 23 ms 1024 KB Output is correct
19 Correct 21 ms 1024 KB Output is correct
20 Correct 22 ms 896 KB Output is correct
21 Execution timed out 2074 ms 8064 KB Time limit exceeded
22 Halted 0 ms 0 KB -

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 29 ms 2176 KB Output is correct
2 Correct 25 ms 2048 KB Output is correct
3 Correct 26 ms 2048 KB Output is correct
4 Correct 27 ms 2048 KB Output is correct
5 Correct 27 ms 2048 KB Output is correct
6 Correct 30 ms 2040 KB Output is correct
7 Correct 30 ms 2048 KB Output is correct
8 Correct 32 ms 2040 KB Output is correct
9 Correct 30 ms 2048 KB Output is correct
10 Correct 30 ms 2048 KB Output is correct
11 Correct 27 ms 2048 KB Output is correct
12 Correct 24 ms 2048 KB Output is correct
13 Correct 25 ms 2048 KB Output is correct
14 Correct 25 ms 2048 KB Output is correct
15 Correct 28 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 11 ms 1024 KB Output is correct
19 Correct 10 ms 1024 KB Output is correct
20 Correct 13 ms 1152 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 428 ms 2424 KB Output is correct
2 Correct 427 ms 2424 KB Output is correct
3 Correct 446 ms 2552 KB Output is correct
4 Correct 438 ms 2424 KB Output is correct
5 Correct 449 ms 2424 KB Output is correct
6 Correct 439 ms 2424 KB Output is correct
7 Correct 439 ms 2424 KB Output is correct
8 Correct 424 ms 2424 KB Output is correct
9 Correct 461 ms 2424 KB Output is correct
10 Correct 427 ms 2504 KB Output is correct
11 Correct 429 ms 2460 KB Output is correct
12 Correct 435 ms 2424 KB Output is correct
13 Correct 429 ms 2364 KB Output is correct
14 Correct 429 ms 2424 KB Output is correct
15 Correct 425 ms 2424 KB Output is correct
16 Correct 19 ms 896 KB Output is correct
17 Correct 22 ms 1024 KB Output is correct
18 Correct 23 ms 1024 KB Output is correct
19 Correct 21 ms 1024 KB Output is correct
20 Correct 22 ms 896 KB Output is correct
21 Execution timed out 2074 ms 8064 KB Time limit exceeded
22 Halted 0 ms 0 KB -