Submission #1074392

#	Time	Username	Problem	Language	Result	Execution time	Memory
1074392		steveonalex	Skyscraper (JOI16_skyscraper)	C++17	100 / 100	183 ms	347372 KiB

skyscraper

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
#define block_of_code if(true)
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(a, b);}
ll lcm(ll a, ll b){return a / gcd(a, b) * b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
double rngesus_d(double l, double r){
    double cur = rngesus(0, MASK(60) - 1);
    cur /= MASK(60) - 1;
    return l + cur * (r - l);
}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }


 
const int MOD = 1e9 + 7;
struct Modular{
    ll x;
    Modular(ll _x = 0){x = _x;}
    Modular& operator += (Modular y){
        x += y.x;
        if (x >= MOD) x -= MOD;
        return *this;
    }
    Modular operator + (Modular y) {
        Modular tmp = *this;
        return tmp += y;
    }
 
    Modular& operator -= (Modular y){
        x -= y.x;
        if (x < 0) x += MOD;
        return *this;
    }
    Modular operator - (Modular y) {
        Modular tmp = *this;
        return tmp -= y;
    }
 
    Modular& operator *= (Modular y){
        x *= y.x;
        if (x >= MOD) x %= MOD;
        return *this;
    }
    Modular operator * (Modular y) {
        Modular tmp = *this;
        return tmp *= y;
    }
 
    // use at your own risk
    bool operator == (Modular y){
        return x == y.x;
    }
    bool operator != (Modular y){
        return x != y.x;
    }
};
ostream& operator << (ostream& out, Modular x){
    out << x.x;
    return out;
}

const int N = 105, L = 1005;
Modular dp[N][N][L][4];
 
int main(void){
    ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
    clock_t start = clock();
 
    int n, l; cin >> n >> l;
    vector<int> a(n);
    for(int i = 0; i<n; ++i) cin >> a[i];

    if (n == 1){
        cout << 1 << "\n";
        return 0;
    }

    sort(ALL(a));

    dp[0][1][0][0] = dp[0][1][0][1] = dp[0][1][0][2] = 1;
    for(int i = 1; i<n; ++i){
        int diff = a[i] - a[i-1];
        for(int j = 1; j <= n; ++j) for(int k = 0; k <= l; ++k) for(int x = 0; x < 4; ++x) if (dp[0][j][k][x] != 0){
            Modular cur = dp[0][j][k][x];
            int _k = k + diff * (j * 2 - pop_cnt(x));
            // add another connected component
            for(int y = -1; y<=1; ++y){
                if (y >= 0 && GETBIT(x, y)) continue;
                int _x = x;
                if (y >= 0) _x += MASK(y);
                Modular next_val = cur;
                if (y == -1) next_val *= (j+1-pop_cnt(x));
                if (_k <= l) dp[1][j+1][_k][_x] += next_val;
            }

            // add to the front or back of an existing component
            for(int y = -1; y<=1; ++y){
                if (y >= 0 && GETBIT(x, y)) continue;
                int _x = x;
                if (y >= 0) _x += MASK(y);
                Modular next_val = cur;
                if (y == -1) next_val *= (j*2-pop_cnt(x));
                if (_k <= l) dp[1][j][_k][_x] += next_val;
            }


            // joining two components
            Modular next_val = cur;
            next_val *= (j-1);
            if (_k <= l) dp[1][j-1][_k][x] += next_val;

            // if (i == 2 && j == 2 && k == 1 && x == 3) {
            //     cout << cur << "\n";
            //     cout << "> " << i+1 << " " << j << " " << _k << " " << x << "\n";
            // }
        }
        for(int j = 0; j <= n; ++j) for(int k = 0; k <= l; ++k) for(int x = 0; x < 4; ++x){
            // if (dp[1][j][k][x] != 0) cout << i + 1 << " " << j << " " << k << " " << x << " " << dp[1][j][k][x] << "\n";
            dp[0][j][k][x] = dp[1][j][k][x];
            dp[1][j][k][x] = 0;
        }
    }

    Modular ans = 0;
    for(int k = 0; k <= l; ++k) ans += dp[0][1][k][3];

    cout << ans << "\n";
 
    cerr << "Time elapsed: " << clock() - start << " ms\n";
    return 0;
}

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