#include <bits/stdc++.h>
using namespace std;
#define int long long
const int mod = 1e9 + 7, M = 105, MAXL = 1005;
int dp[M][M][MAXL][4];
signed main()
{
int n,l;
cin>>n>>l;
int a[n+1];
for (int i=1;i<=n;i++)
cin>>a[i];
sort(a+1,a+n+1);
dp[1][1][0][0]=1;
dp[1][1][0][1]=2;
dp[1][1][0][2]=1;
for (int i=2;i<=n;i++)
for (int j=1;j<=n;j++)
for (int k=0;k<=2;k++)
{
int cst=(a[i]-a[i-1])*(2*j-k);
for (int p=cst;p<=l;p++)
{
dp[i][j+1][p][k]=(dp[i-1][j][p-cst][k]*(j+1-k)+dp[i][j+1][p][k])%mod;
dp[i][j+1][p][k+1]=(dp[i-1][j][p-cst][k]*(2-k)+dp[i][j+1][p][k+1])%mod;
dp[i][j][p][k]=(dp[i-1][j][p-cst][k]*(2*j-k)+dp[i][j][p][k])%mod;
dp[i][j][p][k+1]=(dp[i-1][j][p-cst][k]*(2-k)+dp[i][j][p][k+1])%mod;
dp[i][j-1][p][k]=(dp[i-1][j][p-cst][k]*(j-1)+dp[i][j-1][p][k])%mod;
}
}
int ans=0;
for (int i=0;i<=l;i++)
ans=(ans+dp[n][1][i][2])%mod;
cout<<ans<<endl;
return 0;
}
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |