| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 589385 | Loki_Nguyen | Skyscraper (JOI16_skyscraper) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define ull unsigned long long
#define pb push_back
#define pll pair<int, pii>
#define pii pair<int, int>
#define fi first
#define se second
using namespace std;
const int N = 102;
const int M = 10002;
const int mod = 1e9 + 7;
const int base = 75;
const ll inf = 1e12;
int n, t, tong;
int k, m, a[N], b[N], dp[2][N][M][3];
int ans;
void add(int& x, int y)
{
x += y;
if (x >= mod)
x -= mod;
}
void sol()
{
cin >> n >> k;
for (int i = 1; i <= n; i++)
cin >> a[i], b[i] = i;
if (n == 1)
{
cout << 1 << '\n';
return;
}
sort(a + 1, a + 1 + n);
reverse(a + 1, a + 1 + n);
dp[1][1][a[1] * 2][0] = 1;
dp[1][1][a[1]][1] = 2;
for (int i = 1; i < n; i++)
{
memset(dp[(i&1)^1], 0, sizeof(dp[(i&1)^1]));
for (int j = 1; j <= i; j++)
{
for (int p = 0; p < M; p++)
{
for (int q = 0; q < 3; q++)
{
if (dp[i&1][j][p][q] == 0)
continue;
if (p + a[i + 1] * 2 < M)
add(dp[(i&1)^1)][j + 1][p + a[i + 1] * 2][q], 1ll * dp[i&1][j][p][q] * (j + 1 - q) % mod);
if (q < 2 && p + a[i + 1] < M)
add(dp[(i&1)^1)][j + 1][p + a[i + 1]][q + 1], 1ll * dp[i&1][j][p][q] * (2 - q) % mod);
add(dp[(i&1)^1][j][p][q], 1ll * dp[i&1][j][p][q] * (2 * j - q) % mod);
if (q < 2 && p >= a[i + 1])
add(dp[(i&1)^1)][j][p - a[i + 1]][q + 1], 1ll * dp[i&1][j][p][q] * (2 - q) % mod);
if (j > 1 && p >= a[i + 1] * 2)
add(dp[(i&1)^1)][j - 1][p - a[i + 1] * 2][q], 1ll * dp[i&1][j][p][q] * (j - 1) % mod);
}
}
}
}
for (int i = 0; i <= k; i++)
add(ans, dp[n&1][1][i][2]);
cout << ans << '\n';
}
int main()
{
cin.tie(0);
cout.tie(0);
ios_base::sync_with_stdio(0);
#define task "tests"
if (fopen(task ".inp", "r"))
{
freopen(task ".inp", "r", stdin);
freopen(task ".out", "w", stdout);
}
int test = 1;
// cin >> test;
while (test-- > 0)
sol();
return 0;
}