Submission #1119280

#	Time	Username	Problem	Language	Result	Execution time	Memory
1119280		rahidilbayramli	Skyscraper (JOI16_skyscraper)	C++17	100 / 100	183 ms	79432 KiB

skyscraper

#pragma GCC optimize("-O3")
#include<bits/stdc++.h>
#define ll long long
#define ld long double
#define vl vector<ll>
#define vi vector<int>
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define pb push_back
#define sz(v) (ll)(v.size())
#define f first
#define s second
#define pii pair<int, int>
#define pll pair<ll, ll>
using namespace std;
const ll mod = 1e9+7;
ll dp[102][102][1002][3];
void solve()
{
    ll n, l, i, j, h, k;
    cin >> n >> l;
    ll a[n+5];
    for(i = 1; i <= n; i++)
        cin >> a[i];
    if(n == 1)
    {
        cout << "1\n";
        return;
    }
    sort(a+1, a+n+1);
    dp[0][0][0][0] = 1;
    a[n+1] = a[n];
    for(i = 1; i <= n; i++)
    {
        ll diff = a[i+1] - a[i];
        for(j = 0; j < i; j++)
        {
            for(h = 0; h <= l; h++)
            {
                for(k = 0; k < 3; k++)
                {
                    ll tl = h + (2 * j + 2 - k) * diff;
                    if(tl <= l)
                        dp[i][j+1][tl][k] = ((((j + 1 - k) * dp[i-1][j][h][k]) % mod) + dp[i][j+1][tl][k]) % mod;
                    if(k < 2)
                    {
                        tl = h + (2 * j + 1 - k) * diff;
                        if(tl <= l)
                            dp[i][j+1][tl][k+1] = ((((2 - k) * dp[i-1][j][h][k]) % mod) + dp[i][j+1][tl][k+1]) % mod;
                    }
                    if(j)
                    {
                        tl = h + (2 * j - k) * diff;
                        if(tl <= l)
                            dp[i][j][tl][k] = ((((2 * j - k) * dp[i-1][j][h][k]) % mod) + dp[i][j][tl][k]) % mod;
                        if(k < 2)
                        {
                            tl = h + (2 * j - k - 1) * diff;
                            if(tl <= l)
                                dp[i][j][tl][k+1] = ((((2 - k) * dp[i-1][j][h][k]) % mod) + dp[i][j][tl][k+1]) % mod;
                        }
                    }
                    if(j >= 2)
                    {
                        tl = h + (2 * j - 2 - k) * diff;
                        if(tl <= l)
                            dp[i][j-1][tl][k] = ((((j-1) * dp[i-1][j][h][k]) % mod) + dp[i][j-1][tl][k]) % mod;
                    }
                }
            }
        }
    }
    ll res = 0;
    for(h = 0; h <= l; h++)
    {
        res += dp[n][1][h][2];
        res %= mod;
    }
    cout << res << "\n";
}
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    ll tests = 1;
    //cin >> tests;
    while(tests--)
    {
        solve();
    }
}

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