Submission #528545

#	Time	Username	Problem	Language	Result	Execution time	Memory
528545		aSSSd	Skyscraper (JOI16_skyscraper)	C++14	20 / 100	268 ms	194828 KiB

skyscraper

//#pragma GCC optimize("O2,unroll-loops")
//#pragma GCC target("avx,avx2")
#include <bits/stdc++.h>
using namespace std;
#define in ({int x=0;int c=getchar(),n=0;for(;!isdigit(c);c=getchar()) n=(c=='-');for(;isdigit(c);c=getchar()) x=x*10+c-'0';n?-x:x;})
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rnd(int l,int r)
{
    return l+rng()%(r-l+1);
}
#define fasty ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define forinc(x,a,b) for(int x=a;x<=b;x++)
#define fordec(x,a,b) for(int x=a;x>=b;x--)
#define forv(a,b) for(auto&a:b)
#define fi first
#define se second
#define pb push_back
#define ii pair<long long,long long>
#define getbit(x,i) ((x>>(i))&1)
#define batbit(x,i) (x|(1ll<<(i)))
#define tatbit(x,i) (x&~(1<<(i)))
#define gg exit(0);
#define all(a) a.begin() , a.end()
const int N = 14;
const int mod = 1e9 + 7;
int n, L;
int a[20];
int f[1<<15][15][210];

main()
{
    fasty;
    cin >> n >> L;
    forinc(i,1,n) cin >> a[i];
    if(n <= 10)
    {
        int cnt=0;
        sort(a+1, a+n+1);
        do
        {
            int sum=0;
            forinc(i,1,n-1) sum += abs(a[i] - a[i+1]);
            if(sum <=  L) cnt++;
        }
        while(next_permutation(a+1, a+n + 1));
        cout << cnt;
        return 0;
    }
    f[0][0][0] = 1;
    for(int tt =0 ; tt < (1<<n) - 1 ; tt++) forinc(i, 0, n) forinc(l, 0, L) if(f[tt][i][l])
    {
        for(int j=1; j<=n; ++j) if(!getbit(tt,j-1))
        {
            int tt2=batbit(tt,j-1);
            int c=(tt==0 ? 0 : l + abs(a[i]-a[j]));
            f[tt2][j][c]=(f[tt2][j][c] + f[tt][i][l])%mod;
        }
    }
    int res=0;
    for(int i=1;i<=n;++i) for(int t=0;t<=L;++t) res=(res+f[(1<<n)-1][i][t])%mod;
    cout << res;


}

Compilation message (stderr)

skyscraper.cpp:30:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   30 | main()
      | ^~~~

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