oj.uz

Submission #292976

# Submission time Handle Problem Language Result Execution time Memory
292976 2020-09-07T15:16:20 Z 12tqian Skyscraper (JOI16_skyscraper) C++17
100 / 100
 136 ms 130588 KB 
#include<bits/stdc++.h>
using namespace std;
template<typename A, typename B> ostream& operator<<(ostream &cout, pair<A, B> const &p) {
    return cout << "(" << p.f << ", " << p.s << ")"; }
template<typename A> ostream& operator<<(ostream &cout, vector<A> const &v) {
  cout << "{"; for(int i = 0; i < v.size(); i++) {if (i) cout << ", "; cout << v[i];} return cout << "}"; }
const int MOD = 1e9 + 7;
typedef decay<decltype(MOD)>::type T;
struct mi {
    T val;
    explicit operator T() const { return val; }
    mi() { val = 0; }
    mi(const long long& v) {
        val = (-MOD <= v && v <= MOD) ? v : v % MOD;
        if (val < 0) val += MOD; }
    friend ostream& operator<<(ostream& os, const mi& a) { return os << a.val; }
    friend bool operator==(const mi& a, const mi& b) { return a.val == b.val; }
    friend bool operator!=(const mi& a, const mi& b) { return !(a == b); }
    friend bool operator<(const mi& a, const mi& b) { return a.val < b.val; }
    mi operator-() const { return mi(-val); }
    mi& operator+=(const mi& m) {
        if ((val += m.val) >= MOD) val -= MOD;
        return *this; }
    mi& operator-=(const mi& m) {
        if ((val -= m.val) < 0) val += MOD;
        return *this; }
    mi& operator*=(const mi& m) { val = (long long) val * m.val % MOD;
        return *this; }
    friend mi pow(mi a, long long p) {
        mi ans = 1; assert(p >= 0);
        for (; p; p /= 2, a *= a) if (p & 1) ans *= a;
        return ans; }
    friend mi inv(const mi& a) { assert(a != 0); return pow(a, MOD - 2); }
    mi& operator/=(const mi& m) { return (*this) *= inv(m); }
    friend mi operator+(mi a, const mi& b) { return a += b; }
    friend mi operator-(mi a, const mi& b) { return a -= b; }
    friend mi operator*(mi a, const mi& b) { return a *= b; }
    friend mi operator/(mi a, const mi& b) { return a /= b; }
};
const int MAXN = 105;
const int MAXL = 1005;
const int INF = 10000;
mi dp[MAXN][MAXN][MAXL][3];
int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    int N, L;
    cin >> N >> L;
    vector<int> A(N + 1);
    for (int i = 0; i < N; i++) cin >> A[i];
    A[N] = INF;
    sort(A.begin(), A.end());
    if (N == 1) {
        cout << 1 << '\n';
        return 0;
    }
    int diff = A[1] - A[0];
    if (diff <= L) dp[1][1][diff][1] = 2;
    if (2  * diff <= L) dp[1][1][2 * diff][0] = 1;
    for (int i = 1; i < N; i++) {
        diff = A[i + 1] - A[i];
        for (int j = 1; j <= i; j++) {
            for (int k = 0; k <= L; k++) {
                for (int l = 0; l < 3; l++) {
                    if (dp[i][j][k][l] == 0) continue;
                    if (l < 2 && k + diff * (2 * j - l - 1) <= L) {
                        if (i == N - 1) {
                            assert(j == 1 && l == 1);
                            dp[i + 1][j][k + diff * (2 * j - l - 1)][l + 1] += dp[i][j][k][l] * (2 - l) * j;
                        } else if (l == 0 || j > 1) {
                            dp[i + 1][j][k + diff * (2 * j - l - 1)][l + 1] += dp[i][j][k][l] * (2 - l) * (j - l);
                        }
                        if (k + diff * (2 * j - l + 1) <= L) {
                            dp[i + 1][j + 1][k + diff * (2 * j - l + 1)][l + 1] += dp[i][j][k][l] * (2 - l);
                        }
                    }
                    if (k + diff * (2 * j - l + 2) <= L) {
                        dp[i + 1][j + 1][k + diff * (2 * j - l + 2)][l] += dp[i][j][k][l];
                    }
                    if (k + diff * (2 * j - l) <= L) {
                        dp[i + 1][j][k + diff * (2 * j - l)][l] += dp[i][j][k][l] * (2 * j - l);
                    }
                    if (k + diff * (2 * j - l - 2) <= L && j >= 2 && (i == N - 1 || j > 2 || l < 2)) {
                        if (l == 0) {
                            dp[i + 1][j - 1][k + diff * (2 * j - l - 2)][l] += dp[i][j][k][l] * j * (j - 1);
                        } else if (l == 1) {
                            dp[i + 1][j - 1][k + diff * (2 * j - l - 2)][l] += dp[i][j][k][l] * (j - 1) * (j - 1);
                        } else if (l == 2) {
                            if (i == N - 1) {
                                assert(j == 2);
                                dp[i + 1][j - 1][k + diff * (2 * j - l - 2)][l] += dp[i][j][k][l];
                            } else {
                                dp[i + 1][j - 1][k + diff * (2 * j - l - 2)][l] += dp[i][j][k][l] * (j - 1) * (j - 2);
                            }
                        }
                    }
                }
            }
        }
    }
    mi ans = 0;
    for (int s = 0; s <= L; s++) {
        ans += dp[N][1][s][2];
    }
    cout << ans << '\n';
    return 0;
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 76 ms 130424 KB Output is correct
2 Correct 76 ms 130424 KB Output is correct
3 Correct 88 ms 130388 KB Output is correct
4 Correct 80 ms 130424 KB Output is correct
5 Correct 87 ms 130408 KB Output is correct
6 Correct 79 ms 130392 KB Output is correct
7 Correct 83 ms 130424 KB Output is correct
8 Correct 80 ms 130444 KB Output is correct
9 Correct 78 ms 130424 KB Output is correct
10 Correct 81 ms 130480 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 86 ms 130408 KB Output is correct
2 Correct 81 ms 130396 KB Output is correct
3 Correct 82 ms 130440 KB Output is correct
4 Correct 79 ms 130412 KB Output is correct
5 Correct 79 ms 130488 KB Output is correct
6 Correct 83 ms 130424 KB Output is correct
7 Correct 79 ms 130488 KB Output is correct
8 Correct 83 ms 130424 KB Output is correct
9 Correct 85 ms 130472 KB Output is correct
10 Correct 80 ms 130424 KB Output is correct

Subtask #3
80.0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 76 ms 130424 KB Output is correct
2 Correct 76 ms 130424 KB Output is correct
3 Correct 88 ms 130388 KB Output is correct
4 Correct 80 ms 130424 KB Output is correct
5 Correct 87 ms 130408 KB Output is correct
6 Correct 79 ms 130392 KB Output is correct
7 Correct 83 ms 130424 KB Output is correct
8 Correct 80 ms 130444 KB Output is correct
9 Correct 78 ms 130424 KB Output is correct
10 Correct 81 ms 130480 KB Output is correct
11 Correct 86 ms 130408 KB Output is correct
12 Correct 81 ms 130396 KB Output is correct
13 Correct 82 ms 130440 KB Output is correct
14 Correct 79 ms 130412 KB Output is correct
15 Correct 79 ms 130488 KB Output is correct
16 Correct 83 ms 130424 KB Output is correct
17 Correct 79 ms 130488 KB Output is correct
18 Correct 83 ms 130424 KB Output is correct
19 Correct 85 ms 130472 KB Output is correct
20 Correct 80 ms 130424 KB Output is correct
21 Correct 81 ms 130488 KB Output is correct
22 Correct 136 ms 130424 KB Output is correct
23 Correct 120 ms 130424 KB Output is correct
24 Correct 114 ms 130424 KB Output is correct
25 Correct 129 ms 130532 KB Output is correct
26 Correct 117 ms 130392 KB Output is correct
27 Correct 94 ms 130588 KB Output is correct
28 Correct 100 ms 130428 KB Output is correct
29 Correct 116 ms 130424 KB Output is correct
30 Correct 121 ms 130496 KB Output is correct