Submission #528004

#	Time	Username	Problem	Language	Result	Execution time	Memory
528004		tphuc2908	Skyscraper (JOI16_skyscraper)	C++14	20 / 100	391 ms	476756 KiB

skyscraper

#include<bits/stdc++.h>

using namespace std;
//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx,avx2,fma")
//#pragma GCC optimization ("unroll-loops")
#define rep(i, x, y) for(int i = x; i <= y; ++i)
#define repi(i,x,y) for(int i = x; i >= y; --i)
#define ci(x) int x; cin>> x
#define TC(t) ci(t); while(t--)
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(), x.end()
#define cii(x, y) ci(x); ci(y)
#define ciii(x, y, z) ci(x); ci(y); ci(z)
#define mp make_pair
//#define int long long
typedef long long ll;
typedef vector<int> vi;
const int N = 8e2 + 5;
const int NN = 16 + 15;
const int mod = 1e9+7;
const int mod1 = 1e9 + 9;
const int pi = 31;
const ll inf = 1e15 + 6;
const int block = 500;
const int dx[4] = {-1, 0, 1, 0};
const int dy[4] = {0, -1, 0, 1};

void readfile(){
    #ifdef ONLINE_JUDGE
    #else
        freopen("text.inp", "r", stdin);
    #endif // ONLINE_JUDGE
//    freopen("text.inp", "r", stdin);
//    freopen("template.out", "w", stdout);
}

int n, L;
int a[N];

void inp(){
    cin >> n >> L;
    for(int i = 1; i <= n; ++i) cin >> a[i];
}

int add(int x, int y){
    x += y;
    while(x < 0) x += mod;
    while(x >= mod) x -= mod;
    return x;
}

int mul(int x, int y){
    return (x * 1LL * y) % mod;
}

int f[(1<<14)][14][1005];

void sub2(){
    for(int i = 0; i < n; ++i)
        f[(1<<i)][i][0] = 1;
    for(int i = 0; i < (1<<n); ++i){
        for(int j = 0; j < n; ++j){
            if(!((i>>j)&1)) continue;
            for(int k = 0; k < n; ++k){
                if(!((i>>k)&1)) continue;
                if(k==j) continue;
                for(int w = 0; w <= L; ++w)
                    if(w + abs(a[j+1] - a[k+1]) <= L)
                        f[i][j][w + abs(a[j+1] - a[k+1])] = add(f[i][j][w + abs(a[j+1] - a[k+1])], f[i^(1<<j)][k][w]);
            }
        }
    }
    int res = 0;
    for(int w = 0; w <= L; ++w)
        for(int i = 0; i < n; ++i)
            res = add(res, f[(1<<n)-1][i][w]);
    cout << res;
}

void process(){
    if(n <= 14) sub2();
}

int main() {
    //readfile();
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    inp();
    process();
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'void readfile()':
skyscraper.cpp:34:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |         freopen("text.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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