제출 #60302

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
60302		Benq	Skyscraper (JOI16_skyscraper)	C++11	20 / 100	2056 ms	18184 KiB

skyscraper

#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 N,L;
vi A;
map<array<int,3>,int> m, M;

void MUL(int& a, int b) { a = (ll)a*b % MOD; }
void AD(int& a, int b) { a = (a+b)%MOD; }

void triEnd(int x, array<int,3> a, int b) {
    if (!a[0]) return;
    MUL(b,a[0]); a[0] --; a[2] += x;
    F0R(i,2) F0R(j,2) AD(m[{a[0]+i,a[1]+j,a[2]-i*x-2*j*x}],b);
}

void triMid(int x, array<int,3> a, int b) {
    if (!a[1]) return;
    MUL(b,a[1]), a[1] --; a[2] += 2*x;
    F0R(i,2) F0R(j,2) AD(m[{a[0],a[1]+i+j,a[2]-2*i*x-2*j*x}],b);
}

void ad(int x) {
    swap(m,M); m.clear();
    for (auto a: M) {
        triEnd(x,a.f,a.s);
        triMid(x,a.f,a.s);
    }
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> N >> L; A.resize(N);
    F0R(i,N) cin >> A[i];
    sort(all(A));
    F0R(i,2) F0R(j,2) AD(m[{i+j,0,-(i+j)*A[0]}],1);
    FOR(i,1,sz(A)) ad(A[i]);
    
    int ans = 0;
    for (auto x: m) if (x.f[0] == 0 && x.f[1] == 0 && x.f[2] <= L) AD(ans,x.s);
    // for (auto x: m) if (x.f[0] == 0 && x.f[1] == 0) cout << x.f[2] << " " << x.s << "\n";
    cout << ans;
}

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