oj.uz

Submission #318363

# Submission time Handle Problem Language Result Execution time Memory
318363 2020-11-01T13:02:54 Z a14789654 Skyscraper (JOI16_skyscraper) C++17
100 / 100
 381 ms 180996 KB 
#include <bits/stdc++.h>

using namespace std;

const int MOD = 1e9 + 7, MAXN = 107, MAXL = 1007;

int a[MAXN], f[MAXN][MAXL][2][MAXN][2], n, l;

void add(int &a, int b)
{
    a += b;
    if (a >= MOD) a -= MOD;
}

int calc(int i, int curl, int kl, int k, int kr)
{
    /// kl = 1 if there is a segment connected to the left border, 0 otherwise
    /// kr = 1 if there is a segment connected to the right border, 0 otherwise
    /// k is the number of segments in the middle
    int nxtl = curl;
    if (i) nxtl += (kl + kr + 2 * k) * (a[i] - a[i - 1]); ///Add penalty
    if (nxtl > l) return 0;
    if (k < 0) return 0;
    if (i == n - 1) return !k && (kl || kr);
    if (f[i][curl][kl][k][kr] != - 1) return f[i][curl][kl][k][kr];

    int ans = 0;
    add(ans, calc(i + 1, nxtl, 1, k, kr)); ///Connect to left segmenet
    add(ans, 1LL * calc(i + 1, nxtl, 1, k - 1, kr) * k % MOD); ///Connect to left segment and join to a middle segment

    add(ans, calc(i + 1, nxtl, kl, k, 1)); ///Connect to right segment
    add(ans, 1LL * calc(i + 1, nxtl, kl, k - 1, 1) * k % MOD); /// Connect to right segment and join to a middle segment

    add(ans, calc(i + 1, nxtl, kl, k + 1, kr)); ///Create new segment
    add(ans, 1LL * calc(i + 1, nxtl, kl, k, kr) * k * 2 % MOD); ///Connect to a middle segment
    add(ans, 1LL * k * (k - 1) * calc(i + 1, nxtl, kl, k - 1, kr) % MOD); ///Use to join two middle segments
    return f[i][curl][kl][k][kr] = ans;
}

int main()
{
    if (fopen("tst.inp", "r"))
    {
        freopen("tst.inp", "r", stdin);
        freopen("tst.out", "w", stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    cin >> n >> l;
    if (n == 1) return cout << 1, 0;
    for (int i = 0; i < n; ++i) cin >> a[i];
    sort(a, a + n);
    memset(f, - 1, sizeof(f));
    cout << calc(0, 0, 0, 0, 0);
    return 0;
}

Compilation message

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:44:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   44 |         freopen("tst.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:45:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   45 |         freopen("tst.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 91 ms 180836 KB Output is correct
3 Correct 91 ms 180856 KB Output is correct
4 Correct 92 ms 180976 KB Output is correct
5 Correct 89 ms 180856 KB Output is correct
6 Correct 90 ms 180964 KB Output is correct
7 Correct 89 ms 180836 KB Output is correct
8 Correct 91 ms 180836 KB Output is correct
9 Correct 92 ms 180836 KB Output is correct
10 Correct 98 ms 180996 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 94 ms 180836 KB Output is correct
2 Correct 94 ms 180836 KB Output is correct
3 Correct 94 ms 180840 KB Output is correct
4 Correct 94 ms 180772 KB Output is correct
5 Correct 95 ms 180836 KB Output is correct
6 Correct 93 ms 180836 KB Output is correct
7 Correct 97 ms 180836 KB Output is correct
8 Correct 94 ms 180964 KB Output is correct
9 Correct 93 ms 180856 KB Output is correct
10 Correct 95 ms 180836 KB Output is correct

Subtask #3
80.0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 91 ms 180836 KB Output is correct
3 Correct 91 ms 180856 KB Output is correct
4 Correct 92 ms 180976 KB Output is correct
5 Correct 89 ms 180856 KB Output is correct
6 Correct 90 ms 180964 KB Output is correct
7 Correct 89 ms 180836 KB Output is correct
8 Correct 91 ms 180836 KB Output is correct
9 Correct 92 ms 180836 KB Output is correct
10 Correct 98 ms 180996 KB Output is correct
11 Correct 94 ms 180836 KB Output is correct
12 Correct 94 ms 180836 KB Output is correct
13 Correct 94 ms 180840 KB Output is correct
14 Correct 94 ms 180772 KB Output is correct
15 Correct 95 ms 180836 KB Output is correct
16 Correct 93 ms 180836 KB Output is correct
17 Correct 97 ms 180836 KB Output is correct
18 Correct 94 ms 180964 KB Output is correct
19 Correct 93 ms 180856 KB Output is correct
20 Correct 95 ms 180836 KB Output is correct
21 Correct 97 ms 180768 KB Output is correct
22 Correct 366 ms 180880 KB Output is correct
23 Correct 360 ms 180964 KB Output is correct
24 Correct 332 ms 180840 KB Output is correct
25 Correct 374 ms 180916 KB Output is correct
26 Correct 318 ms 180944 KB Output is correct
27 Correct 167 ms 180836 KB Output is correct
28 Correct 192 ms 180836 KB Output is correct
29 Correct 313 ms 180836 KB Output is correct
30 Correct 381 ms 180836 KB Output is correct