Submission #528547

#	Time	Username	Problem	Language	Result	Execution time	Memory
528547		aSSSd	Skyscraper (JOI16_skyscraper)	C++14	20 / 100	252 ms	194812 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];
    f[0][0][0] = 1;
    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;
    }
    for(int tt =0 ; tt <= (1<<n) - 1 ; tt++) forinc(i , 0 , n) forinc(l , 0 , L) if(f[tt][i][l])
    {
        forinc(j , 1 , n) if(!getbit(tt , j-1))
        {
            int kc=0;
            if(tt != 0) kc = l + abs(a[j] - a[i]);
            int tt2 = batbit(tt , j-1);
            f[tt2][j][kc] = (f[tt2][j][kc] + f[tt][i][l])%mod;
        }

    }
    int res=0;
    forinc(i,1,n) forinc(l , 0 , L) res = (res + f[(1<<n) - 1][i][l])%mod;
    cout << res;


}

Compilation message (stderr)

skyscraper.cpp:29:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   29 | main()
      | ^~~~

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