Submission #61421

#	Time	Username	Problem	Language	Result	Execution time	Memory
61421		Benq	Asceticism (JOI18_asceticism)	C++11	49 / 100	1068 ms	1196 KiB

asceticism

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)

#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()

const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 100001;

int ad(int a, int b) { return (a+b)%MOD; }
int sub(int a, int b) { return (a-b+MOD)%MOD; }
int mul(int a, int b) { return (ll)a*b%MOD; }

int N,K;

vi tra(vi cur) {
    vi CUR(sz(cur)+1);
    F0R(i,sz(cur)) {
        CUR[i] = ad(CUR[i],mul(i+1,cur[i]));
        CUR[i+1] = ad(CUR[i+1],mul(sz(cur)-i,cur[i]));
    }
    return CUR;
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> N >> K; 
    vi cur = {1};
    FOR(i,2,N+1) cur = tra(cur);
    // for (int i: cur) cout << i << " ";
    cout << cur[K-1];
}

/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( ) 
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
*/

• Subtask 1: 4 / 4
• Subtask 2: 20 / 20
• Subtask 3: 25 / 25
• Subtask 4: 0 / 51