Submission #92887

#	Time	Username	Problem	Language	Result	Execution time	Memory
92887		LittleFlowers__	Skyscraper (JOI16_skyscraper)	C++14	20 / 100	369 ms	194680 KiB

skyscraper

#include <bits/stdc++.h>
#define bit(x,i) (1&(x>>(i-1)))
#define on(x,i)  (x|(1<<(i-1)))
using namespace std;
const int M=1e9+7;
int n,l,kq;
int a[15];
int f[1<<15][15][210];
int main()
{
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  cin>>n>>l;
  for(int i=1;i<=n;++i) cin>>a[i];
  if(n<=8)
  {
      sort(a+1,a+n+1);
      do
      {
        int sum=0;
        for(int i=1;i<n;++i) sum+=abs(a[i]-a[i+1]);
        kq+=sum<=l;
      }
      while(next_permutation(a+1,a+n+1));
      return cout<<kq,0;
  }
  f[0][0][0]=1;
  for(int tt=0;tt<(1<<n)-1;++tt) for(int i=0;i<=n;++i) for(int t=0;t<=l;++t) if(f[tt][i][t])
    for(int j=1;j<=n;++j) if(!bit(tt,j))
    {
      int tt2=on(tt,j);
      int c=(tt==0 ? 0 : t + abs(a[i]-a[j]));
      f[tt2][j][c]=(f[tt2][j][c] + f[tt][i][t])%M;
    }
  for(int i=1;i<=n;++i) for(int t=0;t<=l;++t) kq=(kq+f[(1<<n)-1][i][t])%M;
  cout<<kq;
}

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 0 / 80