#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/trie_policy.hpp>
#define pb push_back
#define mp make_pair
#define taskname "A"
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> ii;
typedef tree <int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
const int maxn = 105 + 5;
const int maxl = 1005;
const int mod = 1e9 + 7;
int a[maxn] , n , l;
int dp[maxn][maxn][maxl][3];
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
if(fopen(taskname".INP","r")){
freopen(taskname".INP", "r",stdin);
freopen(taskname".OUT", "w",stdout);
}
cin >> n >> l;
for(int i= 1 ; i <= n ; ++i)cin >> a[i];
sort(a + 1 , a + n + 1);
for(int i = n ; i >= 1 ; --i)a[i] -= a[i - 1];
if(n == 1)return cout << 1 , 0;
dp[1][1][0][0] = 1;
dp[1][1][0][1] = 2;
for(int i = 1 ; i < n ; ++i){
a[i] = a[i + 1];
for(int j = 1 ; j <= i ; ++j){
for(int t = 0 ; t <= l ; ++t){
auto add = [&] (int i , int j , int t , int k , int val){
// assert(val >= 0);
if(t <= l){
dp[i][j][t][k] += val;
// cout << i << " " << j << " " << t << " " << k << " " << dp[i][j][t][k] << endl;
if(dp[i][j][t][k] >= mod)dp[i][j][t][k] -= mod;
}
};
add(i + 1 , j + 1 , t + 2 * j * a[i] , 1 , 2 * dp[i][j][t][0] % mod);//add end or start
add(i + 1 , j , t + 2 * j * a[i] , 1 , (ll)2 * j * dp[i][j][t][0] % mod);//add end or start and connect to 1 component
if(i + 1 < n)add(i + 1 , j + 1 , t + 2 * j * a[i] , 0 , dp[i][j][t][0]);
add(i + 1 , j , t + 2 * j * a[i] , 0 , 2ll * j * dp[i][j][t][0] % mod);
if(j >= 2)add(i + 1 , j - 1 , t + 2 * j * a[i] , 0 , (ll)j * (j - 1) % mod * dp[i][j][t][0] % mod);
add(i + 1 , j + 1 , t + (2 * j - 1) * a[i] , 2 , dp[i][j][t][1]);
if(j > 1)add(i + 1 , j , t + (2 * j - 1) * a[i] , 2 , (ll)(j - 1) * dp[i][j][t][1] % mod);
add(i + 1 , j , t + (2 * j - 1) * a[i] , 1 , dp[i][j][t][1]);
add(i + 1 , j - 1 , t + (2 * j - 1) * a[i] , 1 , 1ll * (j - 1) * dp[i][j][t][1] % mod);
if(i + 1 < n)add(i + 1 , j + 1 , t + (2 * j - 1) * a[i] , 1 , dp[i][j][t][1]);
if(j >= 1)add(i + 1 , j , t + (2 * j - 1) * a[i] , 1 , 2ll * (j - 1) * dp[i][j][t][1] % mod);
if(j >= 3)add(i + 1 , j - 1 , t + (2 * j - 1) * a[i] , 1 , (ll)(j - 1) * (j - 2) % mod * dp[i][j][t][1] % mod);
if(i + 1 < n)add(i + 1 , j + 1 , t + (2 * j - 2) * a[i] , 2 , dp[i][j][t][2]);
add(i + 1 , j , t + (2 * j - 2) * a[i] , 2 , 2 * dp[i][j][t][2] % mod);
add(i + 1 , j - 1, t + (2 * j - 2) * a[i] , 2 , 2ll * (j - 2) * dp[i][j][t][2] % mod);
if(j >= 2)add(i + 1 , j , t + (2 * j - 2) * a[i] , 2 , 2ll * (j - 2) * dp[i][j][t][2] % mod);
if(j >= 4)add(i + 1 , j - 1 , t + (2 * j - 2) * a[i] , 2 , (ll)(j - 2) * (j - 3) % mod * dp[i][j][t][2] % mod);
}
}
}
for(int i = 2 ; i <= n ; ++i){
for(int j = 1 ; j <= i ; ++j){
for(int t = 0 ; t <= l ; ++t){
// cout << i << " " << j << " " << t << " " << dp[i][j][t][0] << " " << dp[i][j][t][1] << " " << dp[i][j][t][2] << endl;
}
}
}
int res = 0;
for(int i = 1 ; i <= l ; ++i){
if(i - 2 * a[n] >= 0){
res += dp[n - 1][2][i - 2 * a[n]][2];
if(res >= mod)res -= mod;
}
if(i - a[n] >= 0){
res += dp[n - 1][1][i - a[n]][1] % mod;
if(res >= mod)res -= mod;
}
}
// cerr << dp[n][1][l][2];
cout << res;
}
Compilation message
skyscraper.cpp: In function 'int main()':
skyscraper.cpp:30:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
freopen(taskname".INP", "r",stdin);
~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:31:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
freopen(taskname".OUT", "w",stdout);
~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
504 KB |
Output is correct |
3 |
Correct |
2 ms |
380 KB |
Output is correct |
4 |
Correct |
2 ms |
376 KB |
Output is correct |
5 |
Correct |
4 ms |
888 KB |
Output is correct |
6 |
Correct |
3 ms |
760 KB |
Output is correct |
7 |
Correct |
3 ms |
504 KB |
Output is correct |
8 |
Correct |
3 ms |
504 KB |
Output is correct |
9 |
Correct |
4 ms |
888 KB |
Output is correct |
10 |
Correct |
3 ms |
632 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
760 KB |
Output is correct |
2 |
Correct |
3 ms |
760 KB |
Output is correct |
3 |
Correct |
3 ms |
888 KB |
Output is correct |
4 |
Correct |
4 ms |
760 KB |
Output is correct |
5 |
Correct |
3 ms |
888 KB |
Output is correct |
6 |
Correct |
3 ms |
1016 KB |
Output is correct |
7 |
Correct |
3 ms |
760 KB |
Output is correct |
8 |
Correct |
3 ms |
888 KB |
Output is correct |
9 |
Correct |
3 ms |
1016 KB |
Output is correct |
10 |
Correct |
3 ms |
768 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
504 KB |
Output is correct |
3 |
Correct |
2 ms |
380 KB |
Output is correct |
4 |
Correct |
2 ms |
376 KB |
Output is correct |
5 |
Correct |
4 ms |
888 KB |
Output is correct |
6 |
Correct |
3 ms |
760 KB |
Output is correct |
7 |
Correct |
3 ms |
504 KB |
Output is correct |
8 |
Correct |
3 ms |
504 KB |
Output is correct |
9 |
Correct |
4 ms |
888 KB |
Output is correct |
10 |
Correct |
3 ms |
632 KB |
Output is correct |
11 |
Correct |
3 ms |
760 KB |
Output is correct |
12 |
Correct |
3 ms |
760 KB |
Output is correct |
13 |
Correct |
3 ms |
888 KB |
Output is correct |
14 |
Correct |
4 ms |
760 KB |
Output is correct |
15 |
Correct |
3 ms |
888 KB |
Output is correct |
16 |
Correct |
3 ms |
1016 KB |
Output is correct |
17 |
Correct |
3 ms |
760 KB |
Output is correct |
18 |
Correct |
3 ms |
888 KB |
Output is correct |
19 |
Correct |
3 ms |
1016 KB |
Output is correct |
20 |
Correct |
3 ms |
768 KB |
Output is correct |
21 |
Correct |
7 ms |
3364 KB |
Output is correct |
22 |
Correct |
206 ms |
37568 KB |
Output is correct |
23 |
Correct |
234 ms |
45256 KB |
Output is correct |
24 |
Correct |
221 ms |
48440 KB |
Output is correct |
25 |
Correct |
238 ms |
45112 KB |
Output is correct |
26 |
Correct |
213 ms |
44116 KB |
Output is correct |
27 |
Correct |
100 ms |
32116 KB |
Output is correct |
28 |
Correct |
122 ms |
35448 KB |
Output is correct |
29 |
Correct |
211 ms |
48500 KB |
Output is correct |
30 |
Correct |
240 ms |
45176 KB |
Output is correct |