답안 #46746 :: oj.uz

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
46746	2018-04-22T16:49:20 Z	Trans	Boat (APIO16_boat)	C++14	100 / 100	1096 ms	10748 KB

boat

#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];
int has[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, 0, n) {
    int hi = mm[b[i]] + 1;
    int lo = mm[a[i] - 1] + 1;
    rep(j, lo, hi) {
      has[j]++;
    }
  }

  rep(i, 1, sz(vi)) {
    int range = vi[i] - vi[i - 1];
    if (range < 2) continue;
    rep(j, 1, has[i] + 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;
    }
  }

  // return 0;

  // 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;
        assert(tot <= has[k]);
        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

#	결과	실행 시간	메모리	Grader output
1	Correct	11 ms	4472 KB	Output is correct
2	Correct	13 ms	4472 KB	Output is correct
3	Correct	11 ms	4536 KB	Output is correct
4	Correct	10 ms	4536 KB	Output is correct
5	Correct	11 ms	4536 KB	Output is correct
6	Correct	10 ms	4536 KB	Output is correct
7	Correct	10 ms	4540 KB	Output is correct
8	Correct	11 ms	4540 KB	Output is correct
9	Correct	10 ms	4552 KB	Output is correct
10	Correct	10 ms	4560 KB	Output is correct
11	Correct	10 ms	4560 KB	Output is correct
12	Correct	10 ms	4692 KB	Output is correct
13	Correct	10 ms	4692 KB	Output is correct
14	Correct	10 ms	4692 KB	Output is correct
15	Correct	10 ms	4692 KB	Output is correct
16	Correct	5 ms	4692 KB	Output is correct
17	Correct	5 ms	4692 KB	Output is correct
18	Correct	6 ms	4692 KB	Output is correct
19	Correct	5 ms	4692 KB	Output is correct
20	Correct	5 ms	4692 KB	Output is correct

Subtask #2
22.0 / 22.0

#	결과	실행 시간	메모리	Grader output
1	Correct	11 ms	4472 KB	Output is correct
2	Correct	13 ms	4472 KB	Output is correct
3	Correct	11 ms	4536 KB	Output is correct
4	Correct	10 ms	4536 KB	Output is correct
5	Correct	11 ms	4536 KB	Output is correct
6	Correct	10 ms	4536 KB	Output is correct
7	Correct	10 ms	4540 KB	Output is correct
8	Correct	11 ms	4540 KB	Output is correct
9	Correct	10 ms	4552 KB	Output is correct
10	Correct	10 ms	4560 KB	Output is correct
11	Correct	10 ms	4560 KB	Output is correct
12	Correct	10 ms	4692 KB	Output is correct
13	Correct	10 ms	4692 KB	Output is correct
14	Correct	10 ms	4692 KB	Output is correct
15	Correct	10 ms	4692 KB	Output is correct
16	Correct	5 ms	4692 KB	Output is correct
17	Correct	5 ms	4692 KB	Output is correct
18	Correct	6 ms	4692 KB	Output is correct
19	Correct	5 ms	4692 KB	Output is correct
20	Correct	5 ms	4692 KB	Output is correct
21	Correct	201 ms	8584 KB	Output is correct
22	Correct	159 ms	8584 KB	Output is correct
23	Correct	151 ms	8584 KB	Output is correct
24	Correct	163 ms	8584 KB	Output is correct
25	Correct	163 ms	8668 KB	Output is correct
26	Correct	280 ms	8668 KB	Output is correct
27	Correct	274 ms	8804 KB	Output is correct
28	Correct	279 ms	8804 KB	Output is correct
29	Correct	310 ms	8932 KB	Output is correct
30	Correct	13 ms	8932 KB	Output is correct
31	Correct	13 ms	8932 KB	Output is correct
32	Correct	13 ms	8932 KB	Output is correct
33	Correct	14 ms	8932 KB	Output is correct
34	Correct	13 ms	8932 KB	Output is correct
35	Correct	14 ms	8932 KB	Output is correct
36	Correct	13 ms	8932 KB	Output is correct
37	Correct	14 ms	8932 KB	Output is correct
38	Correct	13 ms	8932 KB	Output is correct

Subtask #3
27.0 / 27.0

#	결과	실행 시간	메모리	Grader output
1	Correct	6 ms	8932 KB	Output is correct
2	Correct	6 ms	8932 KB	Output is correct
3	Correct	6 ms	8932 KB	Output is correct
4	Correct	7 ms	8932 KB	Output is correct
5	Correct	8 ms	8932 KB	Output is correct
6	Correct	10 ms	8932 KB	Output is correct
7	Correct	10 ms	8932 KB	Output is correct
8	Correct	10 ms	8932 KB	Output is correct
9	Correct	11 ms	8932 KB	Output is correct
10	Correct	10 ms	8932 KB	Output is correct
11	Correct	7 ms	8932 KB	Output is correct
12	Correct	5 ms	8932 KB	Output is correct
13	Correct	7 ms	8932 KB	Output is correct
14	Correct	6 ms	8932 KB	Output is correct
15	Correct	6 ms	8932 KB	Output is correct
16	Correct	6 ms	8932 KB	Output is correct
17	Correct	4 ms	8932 KB	Output is correct
18	Correct	4 ms	8932 KB	Output is correct
19	Correct	4 ms	8932 KB	Output is correct
20	Correct	4 ms	8932 KB	Output is correct

Subtask #4
42.0 / 42.0

#	결과	실행 시간	메모리	Grader output
1	Correct	11 ms	4472 KB	Output is correct
2	Correct	13 ms	4472 KB	Output is correct
3	Correct	11 ms	4536 KB	Output is correct
4	Correct	10 ms	4536 KB	Output is correct
5	Correct	11 ms	4536 KB	Output is correct
6	Correct	10 ms	4536 KB	Output is correct
7	Correct	10 ms	4540 KB	Output is correct
8	Correct	11 ms	4540 KB	Output is correct
9	Correct	10 ms	4552 KB	Output is correct
10	Correct	10 ms	4560 KB	Output is correct
11	Correct	10 ms	4560 KB	Output is correct
12	Correct	10 ms	4692 KB	Output is correct
13	Correct	10 ms	4692 KB	Output is correct
14	Correct	10 ms	4692 KB	Output is correct
15	Correct	10 ms	4692 KB	Output is correct
16	Correct	5 ms	4692 KB	Output is correct
17	Correct	5 ms	4692 KB	Output is correct
18	Correct	6 ms	4692 KB	Output is correct
19	Correct	5 ms	4692 KB	Output is correct
20	Correct	5 ms	4692 KB	Output is correct
21	Correct	201 ms	8584 KB	Output is correct
22	Correct	159 ms	8584 KB	Output is correct
23	Correct	151 ms	8584 KB	Output is correct
24	Correct	163 ms	8584 KB	Output is correct
25	Correct	163 ms	8668 KB	Output is correct
26	Correct	280 ms	8668 KB	Output is correct
27	Correct	274 ms	8804 KB	Output is correct
28	Correct	279 ms	8804 KB	Output is correct
29	Correct	310 ms	8932 KB	Output is correct
30	Correct	13 ms	8932 KB	Output is correct
31	Correct	13 ms	8932 KB	Output is correct
32	Correct	13 ms	8932 KB	Output is correct
33	Correct	14 ms	8932 KB	Output is correct
34	Correct	13 ms	8932 KB	Output is correct
35	Correct	14 ms	8932 KB	Output is correct
36	Correct	13 ms	8932 KB	Output is correct
37	Correct	14 ms	8932 KB	Output is correct
38	Correct	13 ms	8932 KB	Output is correct
39	Correct	6 ms	8932 KB	Output is correct
40	Correct	6 ms	8932 KB	Output is correct
41	Correct	6 ms	8932 KB	Output is correct
42	Correct	7 ms	8932 KB	Output is correct
43	Correct	8 ms	8932 KB	Output is correct
44	Correct	10 ms	8932 KB	Output is correct
45	Correct	10 ms	8932 KB	Output is correct
46	Correct	10 ms	8932 KB	Output is correct
47	Correct	11 ms	8932 KB	Output is correct
48	Correct	10 ms	8932 KB	Output is correct
49	Correct	7 ms	8932 KB	Output is correct
50	Correct	5 ms	8932 KB	Output is correct
51	Correct	7 ms	8932 KB	Output is correct
52	Correct	6 ms	8932 KB	Output is correct
53	Correct	6 ms	8932 KB	Output is correct
54	Correct	6 ms	8932 KB	Output is correct
55	Correct	4 ms	8932 KB	Output is correct
56	Correct	4 ms	8932 KB	Output is correct
57	Correct	4 ms	8932 KB	Output is correct
58	Correct	4 ms	8932 KB	Output is correct
59	Correct	485 ms	9992 KB	Output is correct
60	Correct	405 ms	9992 KB	Output is correct
61	Correct	393 ms	9992 KB	Output is correct
62	Correct	478 ms	9992 KB	Output is correct
63	Correct	450 ms	9992 KB	Output is correct
64	Correct	1096 ms	10656 KB	Output is correct
65	Correct	979 ms	10656 KB	Output is correct
66	Correct	1002 ms	10704 KB	Output is correct
67	Correct	978 ms	10748 KB	Output is correct
68	Correct	1002 ms	10748 KB	Output is correct
69	Correct	401 ms	10748 KB	Output is correct
70	Correct	373 ms	10748 KB	Output is correct
71	Correct	380 ms	10748 KB	Output is correct
72	Correct	399 ms	10748 KB	Output is correct
73	Correct	405 ms	10748 KB	Output is correct
74	Correct	57 ms	10748 KB	Output is correct
75	Correct	72 ms	10748 KB	Output is correct
76	Correct	57 ms	10748 KB	Output is correct
77	Correct	60 ms	10748 KB	Output is correct
78	Correct	61 ms	10748 KB	Output is correct

답안 #46746

Compilation message

Subtask #1 9.0 / 9.0

Subtask #2 22.0 / 22.0

Subtask #3 27.0 / 27.0

Subtask #4 42.0 / 42.0

Subtask #1
9.0 / 9.0

Subtask #2
22.0 / 22.0

Subtask #3
27.0 / 27.0

Subtask #4
42.0 / 42.0