제출 #727406

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
727406		sochu	Skyscraper (JOI16_skyscraper)	C++14	100 / 100	145 ms	77660 KiB

skyscraper

#include <bits/stdc++.h>
//#pragma GCC optimize ("03")
#define FastIO ios_base::sync_with_stdio(false) , cin.tie(0) , cout.tie(0)
#define FILES freopen("in" , "r" , stdin) , freopen("out" , "w" , stdout)
#define ll long long
#define ull unsigned long long
#define ld long double
#define eb emplace_back
#define pb push_back
#define qwerty1 first
#define qwerty2 second
#define qwerty3 -> first
#define qwerty4 -> second
#define umap unordered_map
#define uset unordered_set
#define pii pair < ll , ll >
#define pq priority_queue
#define dbg(x) cerr << #x << ": " << x << '\n'

namespace FastRead
{
    char __buff[5000];ll __lg = 0 , __p = 0;
    char nc()
    {
        if(__lg == __p){__lg = fread(__buff , 1 , 5000 , stdin);__p = 0;if(!__lg) return EOF;}
        return __buff[__p++];
    }
    template<class T>void read(T&__x)
    {
        T __sgn = 1; char __c;while(!isdigit(__c = nc()))if(__c == '-')__sgn = -1;
        __x = __c - '0';while(isdigit(__c = nc()))__x = __x * 10 + __c - '0';__x *= __sgn;
    }
}

using namespace FastRead;
using namespace std;

const ll N = 1e2 + 10;
const ll L = 1e3 + 10;
const ll M = 1e9 + 7;
const ld PI = acos(-1);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

ll n , l;
ll a[N] , dp[N][N][L][3];

void add(ll &x , ll y)
{
    if(y >= M) y %= M;
    x += y;
    if(x >= M) x -= M;
}

signed main()
{
//	#ifndef ONLINE_JUDGE
//		FastIO , FILES;
//	#endif

	ll i , j , s;

	cin >> n >> l;

	for(i = 1 ; i <= n ; i++)
        cin >> a[i];

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

    sort(a + 1 , a + n + 1);

    a[n + 1] = L;

    dp[1][1][0][2] = 1;
    if(a[2] - a[1] <= l) dp[1][1][a[2] - a[1]][1] = 2;
    if(2 * (a[2] - a[1]) <= l) dp[1][1][2 * (a[2] - a[1])][0] = 1;

    for(i = 2 ; i <= n ; i++)
        for(j = 1 ; j <= i ; j++)
        {
            for(s = 0 ; s <= l ; s++)
            {
                ll delta = a[i + 1] - a[i];

                ///concat
                if(s - 2 * j * delta >= 0)
                add(dp[i][j][s][0] , 2 * j * dp[i - 1][j][s - 2 * j * delta][0]);

                if(s - (2 * j - 1) * delta >= 0)
                add(dp[i][j][s][1] , 2 * dp[i - 1][j][s - (2 * j - 1) * delta][0]);
                if(s - (2 * j - 1) * delta >= 0)
                add(dp[i][j][s][1] , (2 * j - 1) * dp[i - 1][j][s - (2 * j - 1) * delta][1]);

                if(s - (2 * j - 2) * delta >= 0)
                add(dp[i][j][s][2] , dp[i - 1][j][s - (2 * j - 2) * delta][1]);
                if(s - (2 * j - 2) * delta >= 0 && 2 * j - 2 >= 0)
                add(dp[i][j][s][2] , (2 * j - 2) * dp[i - 1][j][s - (2 * j - 2) * delta][2]);

                ///merge
                if(s - 2 * j * delta >= 0)
                add(dp[i][j][s][0] , j * dp[i - 1][j + 1][s - 2 * j * delta][0]);
                if(s - (2 * j - 1) * delta >= 0)
                add(dp[i][j][s][1] , j * dp[i - 1][j + 1][s - (2 * j - 1) * delta][1]);
                if(s - (2 * j - 2) * delta >= 0)
                add(dp[i][j][s][2] , j * dp[i - 1][j + 1][s - (2 * j - 2) * delta][2]);

                ///new
                if(s - 2 * (j - 1) * delta - 2 * delta >= 0)
                add(dp[i][j][s][0] , j * dp[i - 1][j - 1][s - 2 * (j - 1) * delta - 2 * delta][0]);

                if(s - 2 * (j - 1) * delta - delta >= 0)
                add(dp[i][j][s][1] , 2 * dp[i - 1][j - 1][s - 2 * (j - 1) * delta - delta][0]);
                if(2 * (j - 1) - 1 >= 0 && s - (2 * (j - 1) - 1) * delta - 2 * delta >= 0 && j - 1 >= 0)
                add(dp[i][j][s][1] , (j - 1) * dp[i - 1][j - 1][s - (2 * (j - 1) - 1) * delta - 2 * delta][1]);

                if(2 * (j - 1) - 1 >= 0 && s - (2 * (j - 1) - 1) * delta - delta >= 0)
                add(dp[i][j][s][2] , dp[i - 1][j - 1][s - (2 * (j - 1) - 1) * delta - delta][1]);
                if(2 * (j - 1) - 2 >= 0 && s - (2 * (j - 1) - 2) * delta - 2 * delta >= 0 && j - 2 >= 0)
                add(dp[i][j][s][2] , (j - 2) * dp[i - 1][j - 1][s - (2 * (j - 1) - 2) * delta - 2 * delta][2]);
            }
        }

    ll ans = 0;

    for(s = 0 ; s <= l ; s++)
        add(ans , dp[n][1][s][2]);

    cout << ans;

    return 0;
}

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