Submission #1120998

#	Time	Username	Problem	Language	Result	Execution time	Memory
1120998		steveonalex	Zapina (COCI20_zapina)	C++17	110 / 110	184 ms	10836 KiB

zapina

#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()

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 LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ll mask){return __builtin_ctzll(mask);}
int logOf(ll mask){return __lg(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);}

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, char separator = ' ', char finish = '\n'){
        for(auto item: container) cout << item << separator;
        cout << 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 % MOD;
        if (x < 0) x += MOD;
    }
    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;
}

Modular fast_pow(Modular a, int n){
    Modular ans = 1;
    while(n > 0){
        if (n & 1) ans *= a;
        a *= a;
        n >>= 1;
    }
    return ans;
}
Modular inverse(Modular a){return fast_pow(a, MOD - 2);}

const int N = 6e5 + 69;
vector<Modular> fact(N), ifact(N);

void prepare(){
    fact[0] = 1;
    for(int i = 1; i<N; ++i) fact[i] = fact[i-1] * i;
    ifact[N - 1] = inverse(fact[N-1]);
    for(int i = N-1; i>=1; --i) ifact[i-1] = ifact[i] * i;
}

Modular C(int n, int k){
    if (k < 0 || k > n) return 0;
    return fact[n] * ifact[k] * ifact[n-k];
}

Modular Catalan(int n){
    if (n % 2 != 0) return 0;
    return C(n, n / 2) - C(n, n / 2 + 1);
}

Modular solve(){
    int n; cin >> n;
    Modular tot = fast_pow(n, n);
    Modular dp[n+1][n+1];
    dp[0][0] = 1;
    for(int i = 0; i < n; ++i) for(int j = 0; j <= n; ++j) for(int k = 0; k <= n - j; ++k) if (k != i+1) {
        dp[i+1][j+k] += dp[i][j] * C(n - j, k);
    }

    return tot - dp[n][n];
}

int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    clock_t start = clock();
    
    prepare();
    cout << solve() << "\n";

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

• Subtask 1: 22 / 22
• Subtask 2: 33 / 33
• Subtask 3: 55 / 55