//Be Name KHODA
#pragma GCC optimize("Ofast")
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define pb push_back
#define pp pop_back
#define lb lower_bound
#define ub upper_bound
#define cl clear
#define bg begin
#define arr(x) array<int , x>
#define endl '\n'
const int MOD = int(1e9) + 7;
int n , k;
vector<int> a;
int dp[(1 << 14)][14][101];
void Add(int &e , int b){
e += b;
if(e > MOD) e -= MOD;
if(e < 0) e += MOD;
}
int Mul(int a , int b){
return (1ll * a * b) % MOD;
}
int Pow(int a , int b){
int res = 1;
while(b){
if((b & 1)) res = Mul(res , a);
a = Mul(a , a) , b >>= 1;
}
return res;
}
void f(){
for(int bit = 0 ; bit < n ; bit++){
dp[msk | (1 << bit)][bit][0] = 1;
}
for(int msk = 1 ; msk < (1 << 14) ; msk++){
for(int bit0 = 0 ; bit0 < n ; bit0++){
if(((msk >> bit0) & 1)) continue;
for(int bit1 = 0 ; bit1 < n ; bit1++){
if(!((msk >> bit1) & 1)) continue;
for(int sm = 0 ; sm <= k ; sm++){
if(sm + abs(a[bit0] - a[bit1]) > k) continue;
Add(dp[msk | (1 << bit0)][bit0][sm + abs(a[bit0] - a[bit1])] , dp[msk][bit1][sm]);
}
}
}
}
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n >> k;
for(int i = 0 ; i < n ; i++){
int d;
cin >> d;
a.pb(d);
}
f();
int o = 0;
for(int end = 0 ; end < n ; end++){
for(int sm = 0 ; sm <= k ; sm++){
Add(o , dp[(1 << n) - 1][end][sm]);
}
}
cout << o;
}
Compilation message
skyscraper.cpp: In function 'void f()':
skyscraper.cpp:41:12: error: 'msk' was not declared in this scope
41 | dp[msk | (1 << bit)][bit][0] = 1;
| ^~~
