# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
112555 | ckodser | Skyscraper (JOI16_skyscraper) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#if __cplusplus >= 201103L
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#endif
int gcd(int a, int b) {return b == 0 ? a : gcd(b, a % b);}
#define ll long long
#define pb push_back
#define ld long double
#define mp make_pair
#define F first
#define S second
#define pii pair<ll,ll>
using namespace :: std;
const ll mod=1e9+7;
const ll maxn=110;
const ll maxl=1010;
inline void jam(ll &a,ll b){a+=b;if(a>=mod)a-=mod;}
inline void jamz(ll &a,long long b,ll c){a+=(b*c)%mod;if(a>=mod)a-=mod;}
inline ll ok(ll a){if(a>=mod)a-=mod;return a;}
inline ll zarb(long long a,ll b){return (a*b)%mod;}
ll a[maxn];
ll dp[maxn][maxn][maxl][4];
inline ll find_inp(ll out,ll t){
return out-(1^(t&1))+(1^(t>>1));
}
int main(){
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
ll n,l;
cin>>n>>l;
for(ll i=1;i<=n;i++){
cin>>a[i];
}
sort(a+1,a+n+1);
dp[0][0][0][3]=1;
for(ll i=0;i<n;i++){
ll d=a[i+1]-a[i];
for(ll out=0;out<=i;out++){
for(ll u=0;u<=l;u++){
for(ll t=0;t<4;t++){
ll v=dp[i][out][u][t];
if(v==0)continue;
ll inp=find_inp(out,t);
ll inpmojaz=(inp-1)+(t>>1);
ll outmojaz=(out-1)+(t&1);
if(inpmojaz != outmojaz){exit(1);out<<"WTF?!!";return 0;}
ll uu=u+d*(inp+out);
if(uu>l)continue;
ll b;
if(t==3 || t==0){
if(i==n-1){
b=zarb(out,inp);
}else{
b=zarb(out,out-1);
}
}
if(t==1 || t==2)b=ok(zarb(out,inp)-min(inp,out)+mod);
jam(dp[i+1][out+1][uu][t],v);
if(out)jamz(dp[i+1][out][uu][t],v,out);
if(inp)jamz(dp[i+1][out][uu][t],v,inp);
if(out && inp)jamz(dp[i+1][out-1][uu][t],v,b);
if(i==n-1){
inpmojaz=inp;
outmojaz=out;
}
if(t&1){
jamz(dp[i+1][out ][uu][t^1],v,inpmojaz);
jam (dp[i+1][out+1][uu][t^1],v);
}
if(t&2){
if(out>=1)jamz(dp[i+1][out-1][uu][t^2],v,outmojaz);
jam (dp[i+1][out ][uu][t^2],v);
}
}
}
}
}
ll ans=0;
for(ll i=0;i<=l;i++){
jam(ans,dp[n][0][i][0]);
}
cout<<ans<<endl;
}