#include <bits/stdc++.h>
#define DEBUG 1
using namespace std;
namespace output{
void __(short x){cout<<x;}
void __(unsigned x){cout<<x;}
void __(int x){cout<<x;}
void __(long long x){cout<<x;}
void __(unsigned long long x){cout<<x;}
void __(double x){cout<<x;}
void __(long double x){cout<<x;}
void __(char x){cout<<x;}
void __(const char*x){cout<<x;}
void __(const string&x){cout<<x;}
void __(bool x){cout<<(x?"true":"false");}
template<class S,class T>
void __(const pair<S,T>&x){__(DEBUG?"(":""),__(x.first),__(DEBUG?", ":" "),__(x.second),__(DEBUG?")":"");}
template<class T>
void __(const vector<T>&x){__(DEBUG?"{":"");bool _=0;for(const auto&v:x)__(_?DEBUG?", ":" ":""),__(v),_=1;__(DEBUG?"}":"");}
template<class T>
void __(const set<T>&x){__(DEBUG?"{":"");bool _=0;for(const auto&v:x)__(_?DEBUG?", ":" ":""),__(v),_=1;__(DEBUG?"}":"");}
template<class T>
void __(const multiset<T>&x){__(DEBUG?"{":"");bool _=0;for(const auto&v:x)__(_?DEBUG?", ":" ":""),__(v),_=1;__(DEBUG?"}":"");}
template<class S,class T>
void __(const map<S,T>&x){__(DEBUG?"{":"");bool _=0;for(const auto&v:x)__(_?DEBUG?", ":" ":""),__(v),_=1;__(DEBUG?"}":"");}
void pr(){cout<<"\n";}
template<class S,class... T>
void pr(const S&a,const T&...b){__(a);if(sizeof...(b))__(' ');pr(b...);}
}
using namespace output;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<int,char> pic;
typedef pair<double,double> pdd;
typedef pair<ld,ld> pld;
typedef vector<int> vi;
typedef vector<ll> vl;
#define pb push_back
#define fox(i,x,y) for(int i=(x);i<=(y);i++)
#define foxr(i,x,y) for(int i=(y);i>=(x);i--)
const int MN = 105, MM = 1001, mod = 1e9+7;
int N, L, arr[MN], dp[MN][MN][MM][3], i, j, k, l;
inline void add(int &x,int y){x+=y; while(x>=mod)x-=mod;}
int main(){
scanf("%d%d",&N,&L);
for(i=1;i<=N;i++)
scanf("%d",&arr[i]);
if(N==1){
printf("1\n");
return 0;
}
else if(N==2){
printf("%d\n",abs(arr[1]-arr[2])<=L?2:0);
return 0;
}
sort(arr+1,arr+N+1);
arr[N+1]=100000;
dp[1][0][0][0] = 1;
for(i=1;i<=N;i++){
int dif = arr[i+1]-arr[i];
for(j=0;j<=i;j++){
for(k=0;k<=L;k++){
for(l=0;l<=2;l++){
if(!dp[i][j][k][l]) continue;
// add new cc
if(k+dif*(2*j-l+2)<=L) add(dp[i+1][j+1][k+dif*(2*j-l+2)][l],dp[i][j][k][l]);
// merge onto old cc
if(k+dif*(2*j-l)<=L) add(dp[i+1][j][k+dif*(2*j-l)][l],1LL*dp[i][j][k][l]*(2*j-l)%mod);
// merge two cc's
// "bring the cc's out of the ether"
if(j>=2&&(i==N||j>2||k<2)){
if(l==0&&k+dif*(2*j-l-2)<=L) add(dp[i+1][j-1][k+dif*(2*j-l-2)][l],1LL*dp[i][j][k][l]*j%mod*(j-1)%mod);
if(l==1&&k+dif*(2*j-l-2)<=L) add(dp[i+1][j-1][k+dif*(2*j-l-2)][l],1LL*dp[i][j][k][l]*(j-1)%mod*(j-1)%mod);
if(l==2&&k+dif*(2*j-l-2)<=L&&i!=N) add(dp[i+1][j-1][k+dif*(2*j-l-2)][l],1LL*dp[i][j][k][l]*(j-1)%mod*(j-2)%mod);
if(l==2&&k+dif*(2*j-l-2)<=L&&i==N) add(dp[i+1][j-1][k+dif*(2*j-l-2)][l],dp[i][j][k][l]);
}
// sketchy endpoint cancer
if(l<2){
// either endpoint
int coef = 2-l;
// just add it
if(k+dif*(2*j-l+1)<=L) add(dp[i+1][j+1][k+dif*(2*j-l+1)][l+1],dp[i][j][k][l]*coef%mod);
// connects with some cc
if(j-l>0&&k+dif*(2*j-l-1)<=L) add(dp[i+1][j][k+dif*(2*j-l-1)][l+1],dp[i][j][k][l]*coef%mod*(j-l)%mod);
if(j&&k+dif*(2*j-l-1)<=L&&i==N) add(dp[i+1][j][k+dif*(2*j-l-1)][l+1],dp[i][j][k][l]);
}
}
}
}
}
int ans = 0;
for(i=0;i<=L;i++){
ans += dp[N+1][1][i][2]%mod;
if(ans>=mod) ans-=mod;
}
printf("%d\n",ans);
return 0;
}
Compilation message
skyscraper.cpp: In function 'int main()':
skyscraper.cpp:53:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d",&N,&L);
~~~~~^~~~~~~~~~~~~~
skyscraper.cpp:55:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d",&arr[i]);
~~~~~^~~~~~~~~~~~~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
5 ms |
376 KB |
Output is correct |
| 2 |
Correct |
4 ms |
256 KB |
Output is correct |
| 3 |
Correct |
5 ms |
376 KB |
Output is correct |
| 4 |
Incorrect |
5 ms |
376 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
5 ms |
632 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
5 ms |
376 KB |
Output is correct |
| 2 |
Correct |
4 ms |
256 KB |
Output is correct |
| 3 |
Correct |
5 ms |
376 KB |
Output is correct |
| 4 |
Incorrect |
5 ms |
376 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
