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Submission #46730

# Submission time Handle Problem Language Result Execution time Memory
46730 2018-04-22T16:06:27 Z Trans Boat (APIO16_boat) C++14
58 / 100
 2000 ms 12620 KB 
#include <bits/stdc++.h>

using namespace std;

#define rep(i, a, b) for (int i = (a); i < (b); i++)
#define repd(i, a, b) for (int i = (a) - 1; i >= b; i--)
#define pb push_back
#define fi first
#define se second
#define sz(a) ((int)a.size())

typedef long long ll;

const int mod = 1e9 + 7;
const int maxn = 1e3 + 5;

int n, a[maxn], b[maxn];
ll precal[maxn][maxn], inv[maxn];
map<int, int> mm;
ll dp[maxn][maxn], f[maxn];
vector<ll> vi;

ll power_mod(ll a, ll b) {
  ll res = 1;
  while (b) {
    if (b % 2) res = res * a % mod;
    a = a * a % mod;
    b >>= 1;
  }
  return res;
}

int main() {
  rep(i, 1, maxn) {
    inv[i] = power_mod(i, mod - 2);
  }

  cin >> n;

  // mm[0];
  rep(i, 0, n) {
    cin >> a[i] >> b[i];
    mm[a[i] - 1]++;
    mm[b[i]]++;
  }

  int cnt = 0;
  for (auto it = mm.begin(); it != mm.end(); it++) {
    it->se = cnt++;
    vi.pb(it->fi);
  }

  rep(i, 1, sz(vi)) {
    int range = vi[i] - vi[i - 1];
    if (range < 2) continue;
    rep(j, 1, n + 1) {
      // if (j > range) {
      //   precal[i][j] = precal[i][j - 1];
      //   continue;
      // }
      ll cur1 = 1; // Cij
      ll cur2 = (ll) range * (range - 1) / 2; // Cirange
      cur2 %= mod;
      ll res = cur1 * cur2 % mod;
      int tar = min(range - 2, j - 2);
      rep(k, 1, tar + 1) {
        cur1 = cur1 * (ll) (j  - k - 1) % mod * inv[k] % mod;
        cur2 = cur2 * (ll) (range - k - 1) % mod * inv[k + 2] % mod;
        res = (res + cur1 * cur2 % mod) % mod;
      }
      precal[i][j] = res;
    }
  }

  // cout << precal[3][3] << ' ' << precal[3][2] << endl;

  ll ans = 0;
  rep(i, 0, n) {
    int hi = mm[b[i]] + 1;
    int lo = mm[a[i] - 1] + 1;
    dp[i][0] = 1; // ntc
    repd(k, hi, lo) {
      ll ways = (vi[k] - vi[k - 1]) * (i ? dp[i - 1][k - 1] : 1) % mod;
      int tot = 1;
      repd(j, i, 0) {
        if (b[j] < vi[k - 1] + 1 || a[j] > vi[k]) continue;
        tot++;
        // cout << i << ' ' << k << ' ' << vi[k] - vi[k - 1] << ' ' << tot << endl;
        ways += (((j ? dp[j - 1][k - 1] : 1) * precal[k][tot]) % mod);
        if (precal[k][tot] == 0) break;
        ways %= mod;
      }
      // cout << i << ' ' << k << ' ' << ways << endl;
      dp[i][k] = ways;
    }
    rep(k, 1, cnt) {
      dp[i][k] = (dp[i][k] + f[k]) % mod;
      // if (i == 2) cout << f[k] << endl;
      f[k] = dp[i][k];
      dp[i][k] = (dp[i][k] + dp[i][k - 1]) % mod;
      ans = dp[i][k];
    }
  }

  // cout << ans << endl;
  cout << ((ans - 1 + mod) % mod) << '\n';
  return 0;
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 939 ms 8312 KB Output is correct
2 Correct 936 ms 8400 KB Output is correct
3 Correct 934 ms 8436 KB Output is correct
4 Correct 936 ms 8608 KB Output is correct
5 Correct 932 ms 8608 KB Output is correct
6 Correct 927 ms 8612 KB Output is correct
7 Correct 923 ms 8616 KB Output is correct
8 Correct 935 ms 8616 KB Output is correct
9 Correct 940 ms 8744 KB Output is correct
10 Correct 990 ms 8744 KB Output is correct
11 Correct 936 ms 8744 KB Output is correct
12 Correct 938 ms 8744 KB Output is correct
13 Correct 1008 ms 8796 KB Output is correct
14 Correct 948 ms 8828 KB Output is correct
15 Correct 946 ms 8828 KB Output is correct
16 Correct 180 ms 8828 KB Output is correct
17 Correct 177 ms 8828 KB Output is correct
18 Correct 171 ms 8828 KB Output is correct
19 Correct 179 ms 8828 KB Output is correct
20 Correct 177 ms 8828 KB Output is correct

Subtask #2
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 939 ms 8312 KB Output is correct
2 Correct 936 ms 8400 KB Output is correct
3 Correct 934 ms 8436 KB Output is correct
4 Correct 936 ms 8608 KB Output is correct
5 Correct 932 ms 8608 KB Output is correct
6 Correct 927 ms 8612 KB Output is correct
7 Correct 923 ms 8616 KB Output is correct
8 Correct 935 ms 8616 KB Output is correct
9 Correct 940 ms 8744 KB Output is correct
10 Correct 990 ms 8744 KB Output is correct
11 Correct 936 ms 8744 KB Output is correct
12 Correct 938 ms 8744 KB Output is correct
13 Correct 1008 ms 8796 KB Output is correct
14 Correct 948 ms 8828 KB Output is correct
15 Correct 946 ms 8828 KB Output is correct
16 Correct 180 ms 8828 KB Output is correct
17 Correct 177 ms 8828 KB Output is correct
18 Correct 171 ms 8828 KB Output is correct
19 Correct 179 ms 8828 KB Output is correct
20 Correct 177 ms 8828 KB Output is correct
21 Correct 183 ms 10576 KB Output is correct
22 Correct 172 ms 10592 KB Output is correct
23 Correct 163 ms 10592 KB Output is correct
24 Correct 184 ms 10692 KB Output is correct
25 Correct 182 ms 10692 KB Output is correct
26 Correct 278 ms 10692 KB Output is correct
27 Correct 284 ms 10692 KB Output is correct
28 Correct 293 ms 10692 KB Output is correct
29 Correct 322 ms 10692 KB Output is correct
30 Correct 887 ms 12156 KB Output is correct
31 Correct 923 ms 12156 KB Output is correct
32 Correct 907 ms 12156 KB Output is correct
33 Correct 908 ms 12156 KB Output is correct
34 Correct 886 ms 12156 KB Output is correct
35 Correct 881 ms 12156 KB Output is correct
36 Correct 888 ms 12156 KB Output is correct
37 Correct 897 ms 12156 KB Output is correct
38 Correct 960 ms 12156 KB Output is correct

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 12156 KB Output is correct
2 Correct 19 ms 12156 KB Output is correct
3 Correct 20 ms 12156 KB Output is correct
4 Correct 20 ms 12156 KB Output is correct
5 Correct 22 ms 12156 KB Output is correct
6 Correct 20 ms 12156 KB Output is correct
7 Correct 20 ms 12156 KB Output is correct
8 Correct 20 ms 12156 KB Output is correct
9 Correct 20 ms 12156 KB Output is correct
10 Correct 30 ms 12156 KB Output is correct
11 Correct 38 ms 12156 KB Output is correct
12 Correct 20 ms 12156 KB Output is correct
13 Correct 19 ms 12156 KB Output is correct
14 Correct 19 ms 12156 KB Output is correct
15 Correct 19 ms 12156 KB Output is correct
16 Correct 10 ms 12156 KB Output is correct
17 Correct 9 ms 12156 KB Output is correct
18 Correct 10 ms 12156 KB Output is correct
19 Correct 10 ms 12156 KB Output is correct
20 Correct 10 ms 12156 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 939 ms 8312 KB Output is correct
2 Correct 936 ms 8400 KB Output is correct
3 Correct 934 ms 8436 KB Output is correct
4 Correct 936 ms 8608 KB Output is correct
5 Correct 932 ms 8608 KB Output is correct
6 Correct 927 ms 8612 KB Output is correct
7 Correct 923 ms 8616 KB Output is correct
8 Correct 935 ms 8616 KB Output is correct
9 Correct 940 ms 8744 KB Output is correct
10 Correct 990 ms 8744 KB Output is correct
11 Correct 936 ms 8744 KB Output is correct
12 Correct 938 ms 8744 KB Output is correct
13 Correct 1008 ms 8796 KB Output is correct
14 Correct 948 ms 8828 KB Output is correct
15 Correct 946 ms 8828 KB Output is correct
16 Correct 180 ms 8828 KB Output is correct
17 Correct 177 ms 8828 KB Output is correct
18 Correct 171 ms 8828 KB Output is correct
19 Correct 179 ms 8828 KB Output is correct
20 Correct 177 ms 8828 KB Output is correct
21 Correct 183 ms 10576 KB Output is correct
22 Correct 172 ms 10592 KB Output is correct
23 Correct 163 ms 10592 KB Output is correct
24 Correct 184 ms 10692 KB Output is correct
25 Correct 182 ms 10692 KB Output is correct
26 Correct 278 ms 10692 KB Output is correct
27 Correct 284 ms 10692 KB Output is correct
28 Correct 293 ms 10692 KB Output is correct
29 Correct 322 ms 10692 KB Output is correct
30 Correct 887 ms 12156 KB Output is correct
31 Correct 923 ms 12156 KB Output is correct
32 Correct 907 ms 12156 KB Output is correct
33 Correct 908 ms 12156 KB Output is correct
34 Correct 886 ms 12156 KB Output is correct
35 Correct 881 ms 12156 KB Output is correct
36 Correct 888 ms 12156 KB Output is correct
37 Correct 897 ms 12156 KB Output is correct
38 Correct 960 ms 12156 KB Output is correct
39 Correct 19 ms 12156 KB Output is correct
40 Correct 19 ms 12156 KB Output is correct
41 Correct 20 ms 12156 KB Output is correct
42 Correct 20 ms 12156 KB Output is correct
43 Correct 22 ms 12156 KB Output is correct
44 Correct 20 ms 12156 KB Output is correct
45 Correct 20 ms 12156 KB Output is correct
46 Correct 20 ms 12156 KB Output is correct
47 Correct 20 ms 12156 KB Output is correct
48 Correct 30 ms 12156 KB Output is correct
49 Correct 38 ms 12156 KB Output is correct
50 Correct 20 ms 12156 KB Output is correct
51 Correct 19 ms 12156 KB Output is correct
52 Correct 19 ms 12156 KB Output is correct
53 Correct 19 ms 12156 KB Output is correct
54 Correct 10 ms 12156 KB Output is correct
55 Correct 9 ms 12156 KB Output is correct
56 Correct 10 ms 12156 KB Output is correct
57 Correct 10 ms 12156 KB Output is correct
58 Correct 10 ms 12156 KB Output is correct
59 Execution timed out 2023 ms 12620 KB Time limit exceeded
60 Halted 0 ms 0 KB -