제출 #1174743

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1174743		chikien2009	Skyscraper (JOI16_skyscraper)	C++20	100 / 100	123 ms	120236 KiB

skyscraper

#include <bits/stdc++.h>

using namespace std;

void setup()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

long long n, a[105], b, l;
long long f[105][105][1005][3], mod = 1e9 + 7, res;

void Add(long long &ina, long long inb)
{
    ina = (ina + inb) % mod;
}

long long Mul(long long ina, long long inb)
{
    return (ina * inb) % mod;
}

int main()
{
    setup();

    cin >> n >> l;
    for (long long i = 1; i <= n; ++i)
    {
        cin >> a[i];
    }
    sort(a + 1, a + n + 1);
    f[0][0][0][0] = 1;
    for (long long i = 0; i < n; ++i)
    {
        for (long long j = 0; j <= i; ++j)
        {
            for (long long k = 0; k <= l; ++k)
            {
                for (long long g = 0; g <= 2; ++g)
                {
                    f[i][j][k][g] %= mod;
                    b = (a[i + 1] - a[i]) * (2 * j - g) + k;
                    if (b < 0 || b > l || f[i][j][k][g] == 0)
                    {
                        continue;
                    }
                    Add(f[i + 1][j + 1][b][g], Mul(f[i][j][k][g], j + 1 - g));
                    if (g < 2)
                    {
                        Add(f[i + 1][j + 1][b][g + 1], Mul(f[i][j][k][g], 2 - g));
                    }
                    if (j > 0)
                    {
                        Add(f[i + 1][j][b][g], Mul(f[i][j][k][g], 2 * j - g));
                        if (g < 2)
                        {
                            Add(f[i + 1][j][b][g + 1], Mul(f[i][j][k][g], 2 - g));
                        }
                    }
                    if (1 < j)
                    {
                        Add(f[i + 1][j - 1][b][g], Mul(f[i][j][k][g], j - 1));
                    }
                }
            }
        }
    }
    for (long long i = 0; i <= l; ++i)
    {
        res += f[n][1][i][2];
    }
    cout << (n > 1 ? res % mod : 1LL);
    return 0;
}

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