Submission #1139411

#	Time	Username	Problem	Language	Result	Execution time	Memory
1139411		GGOSHAB	Skyscraper (JOI16_skyscraper)	C++20	100 / 100	115 ms	118468 KiB

skyscraper

#ifdef ONPC
    #define _GLIBCXX_DEBUG
#endif
#include <bits/stdc++.h>

#ifndef ONPC
    #pragma GCC target("avx2")
    #pragma GCC target("popcnt")

    #define cerr if (false) cerr
#endif

#define all(v) begin(v), end(v)
#define watch(x) cerr << #x << ':' << x << endl;

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

typedef pair<int, int> Pint;
typedef pair<ll, ll> Pll;

typedef __int128_t int128;

mt19937_64 gen64(chrono::steady_clock::now().time_since_epoch().count());
inline ll rnd(ll l = LLONG_MIN, ll r = LLONG_MAX) {
    return uniform_int_distribution<ll>(l, r)(gen64);
}

const int mod = 1e9 + 7;

inline ll mult(ll a, ll b) {
    return (a * b) % mod;
}

const int inf = 1e9 + 10;
const ll INF = 1e18 + 10;

const int maxn = 100 + 10, maxc = 1e3 + 10;

ll dp[maxn][maxn][maxc][3];

void solve() {
    int n, l;
    cin >> n >> l;
    vector<int> a(n);
    for (auto &i : a) {
        cin >> i;
    }
    if (n == 1) {
        cout << 1 << '\n';
        return;
    }
    a.push_back(-maxc);
    a.push_back(maxc);
    sort(all(a));

    dp[0][0][0][0] = 1;
    for (ll i = 1; i <= n; ++i) {
        for (ll j = 1; j <= i; ++j) {
            for (ll l = 0; l < 3; ++l) {
                int delta = (2 * j - l) * (a[i + 1] - a[i]);
                for (ll k = delta; k < maxc; ++k) {
                    dp[i][j][k][l] += dp[i - 1][j - 1][k - delta][l];
                    if (l > 0) {
                        dp[i][j][k][l] += (3 - l) * dp[i - 1][j - 1][k - delta][l - 1];
                    }

                    dp[i][j][k][l] += (2 * j - l) * dp[i - 1][j][k - delta][l];
                    if (l == 1) {
                        dp[i][j][k][l] += 2 * j * dp[i - 1][j][k - delta][l - 1];
                    }
                    if (l == 2) {
                        if (i == n) {
                            dp[i][j][k][l] += dp[i - 1][j][k - delta][l - 1];
                        } else {
                            dp[i][j][k][l] += (j - 1) * dp[i - 1][j][k - delta][l - 1];
                        }
                    }

                    if (l == 0) {
                        dp[i][j][k][l] += j * (j + 1) * dp[i - 1][j + 1][k - delta][l];
                    }
                    if (l == 1) {
                        dp[i][j][k][l] += j * j * dp[i - 1][j + 1][k - delta][l];
                    }
                    if (l == 2) {
                        if (i == n && j == 1) {
                            dp[i][j][k][l] += dp[i - 1][j + 1][k - delta][l];
                        } else if (i != n) {
                            dp[i][j][k][l] += j * (j - 1) * dp[i - 1][j + 1][k - delta][l];
                        }
                    }
                    dp[i][j][k][l] %= mod;
                }
            }
        }
    }

    ll ans = 0;
    for (int k = 0; k <= l; ++k) {
        ans = (ans + dp[n][1][k][2]) % mod;
    }
    cout << ans << '\n';
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);

    int t = 1;
//    cin >> t;
    while (t--) {
        solve();
    }

    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 80 / 80