//#pragma GCC optimize("O2,unroll-loops")
//#pragma GCC target("avx,avx2")
#include <bits/stdc++.h>
using namespace std;
#define in ({int x=0;int c=getchar(),n=0;for(;!isdigit(c);c=getchar()) n=(c=='-');for(;isdigit(c);c=getchar()) x=x*10+c-'0';n?-x:x;})
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rnd(int l,int r)
{
return l+rng()%(r-l+1);
}
#define fasty ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define forinc(x,a,b) for(int x=a;x<=b;x++)
#define fordec(x,a,b) for(int x=a;x>=b;x--)
#define forv(a,b) for(auto&a:b)
#define fi first
#define se second
#define pb push_back
#define ii pair<long long,long long>
#define getbit(x,i) ((x>>(i))&1)
#define batbit(x,i) (x|(1ll<<(i)))
#define tatbit(x,i) (x&~(1<<(i)))
#define gg exit(0);
#define all(a) a.begin() , a.end()
const int N = 14;
const int mod = 1e9 + 7;
int n, L;
int a[20];
int f[1<<15][15][210];
main()
{
fasty;
cin >> n >> L;
forinc(i,1,n) cin >> a[i];
if(n <= 10)
{
int cnt=0;
sort(a+1, a+n+1);
do
{
int sum=0;
forinc(i,1,n-1) sum += abs(a[i] - a[i+1]);
if(sum <= L) cnt++;
}
while(next_permutation(a+1, a+n + 1));
cout << cnt;
return 0;
}
f[0][0][0] = 1;
for(int tt =0 ; tt < (1<<n) - 1 ; tt++) forinc(i, 0, n) forinc(l, 0, L) if(f[tt][i][l])
{
for(int j=1; j<=n; ++j) if(!getbit(tt,j-1))
{
int tt2=batbit(tt,j-1);
int c=(tt==0 ? 0 : l + abs(a[i]-a[j]));
f[tt2][j][c]=(f[tt2][j][c] + f[tt][i][l])%mod;
}
}
int res=0;
for(int i=1;i<=n;++i) for(int t=0;t<=l;++t) res=(res+f[(1<<n)-1][i][t])%mod;
cout << res;
}
Compilation message
skyscraper.cpp:30:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
30 | main()
| ^~~~
skyscraper.cpp: In function 'int main()':
skyscraper.cpp:60:42: error: 'l' was not declared in this scope
60 | for(int i=1;i<=n;++i) for(int t=0;t<=l;++t) res=(res+f[(1<<n)-1][i][t])%mod;
| ^
