Submission #727023

#	Time	Username	Problem	Language	Result	Execution time	Memory
727023		sochu	Skyscraper (JOI16_skyscraper)	C++14	20 / 100	1513 ms	55552 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 = 4e3 + 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];
//array < array < array < ll , 4 >  , 2 * L > , N > dp1 , dp_old;
ll curr_dp[N][2 * L][4] , old_dp[N][2 * L][4];

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];

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

    old_dp[1][0 + L][0] = 1;
    old_dp[1][-a[1] + L][1] = 1;
    old_dp[1][-a[1] + L][2] = 1;
    old_dp[1][-2 * a[1] + L][3] = 1;

    for(i = 2 ; i <= n ; i++)
    {
        for(j = 1 ; j <= i ; j++)
        {
            for(s = -4 * l ; s <= 2 * l ; s++)
            {
                curr_dp[j][s + L][0] = curr_dp[j][s + L][1] = curr_dp[j][s + L][2] = curr_dp[j][s + L][3] = 0;

                ///merge
                if(s - 2 * a[i] + L >= 0)
                {
                    add(curr_dp[j][s + L][0] , 1ll * j * old_dp[j + 1][s - 2 * a[i] + L][0]);
                    add(curr_dp[j][s + L][1] , 1ll * j * old_dp[j + 1][s - 2 * a[i] + L][1]);
                    add(curr_dp[j][s + L][2] , 1ll * j * old_dp[j + 1][s - 2 * a[i] + L][2]);
                    add(curr_dp[j][s + L][3] , 1ll * j * old_dp[j + 1][s - 2 * a[i] + L][3]);
                }

                ///concat
                add(curr_dp[j][s + L][0] , 1ll * (2 * j - 2) * old_dp[j][s + L][0]);
                add(curr_dp[j][s + L][1] , 1ll * (2 * j - 2) * old_dp[j][s + L][1]);
                add(curr_dp[j][s + L][2] , 1ll * (2 * j - 2) * old_dp[j][s + L][2]);
                add(curr_dp[j][s + L][3] , 1ll * (2 * j - 2) * old_dp[j][s + L][3]);


                if(s - a[i] + L >= 0) add(curr_dp[j][s + L][0] , old_dp[j][s - a[i] + L][1]);
                if(s - a[i] + L >= 0) add(curr_dp[j][s + L][2] , old_dp[j][s - a[i] + L][3]);
                                      add(curr_dp[j][s + L][1] , old_dp[j][s        + L][1]);
                                      add(curr_dp[j][s + L][3] , old_dp[j][s        + L][3]);
                                     // add(curr_dp[j][s + L][3] , old_dp[j][s        + L][1]);

                if(s - a[i] + L >= 0) add(curr_dp[j][s + L][0] , old_dp[j][s - a[i] + L][2]);
                                      add(curr_dp[j][s + L][2] , old_dp[j][s        + L][2]);
                                      add(curr_dp[j][s + L][3] , old_dp[j][s        + L][3]);
                if(s - a[i] + L >= 0) add(curr_dp[j][s + L][1] , old_dp[j][s - a[i] + L][3]);
                                     // add(curr_dp[j][s + L][3] , old_dp[j][s        + L][2]);


                ///new
                if(j > 2 && s + 2 * a[i] + L < 2 * L)
                {
                    add(curr_dp[j][s + L][0] , 1ll * (j - 2) * old_dp[j - 1][s + 2 * a[i] + L][0]);
                    add(curr_dp[j][s + L][1] , 1ll * (j - 2) * old_dp[j - 1][s + 2 * a[i] + L][1]);
                    add(curr_dp[j][s + L][2] , 1ll * (j - 2) * old_dp[j - 1][s + 2 * a[i] + L][2]);
                    add(curr_dp[j][s + L][3] , 1ll * (j - 2) * old_dp[j - 1][s + 2 * a[i] + L][3]);
                }

                if(s + a[i] + L < 2 * L) add(curr_dp[j][s + L][0] , old_dp[j - 1][s +     a[i] + L][1]);
                if(s + a[i] + L < 2 * L) add(curr_dp[j][s + L][0] , old_dp[j - 1][s +     a[i] + L][2]);
                if(s + 2 * a[i] + L < 2 * L) add(curr_dp[j][s + L][1] , old_dp[j - 1][s + 2 * a[i] + L][1]);
                if(s + 2 * a[i] + L < 2 * L)                      add(curr_dp[j][s + L][2] , old_dp[j - 1][s + 2 * a[i] + L][2]);
                if(s + 2 * a[i] + L < 2 * L)                    add(curr_dp[j][s + L][3] , old_dp[j - 1][s + 2 * a[i] + L][3]);
                 if(s + 2 * a[i] + L < 2 * L)                     add(curr_dp[j][s + L][3] , old_dp[j - 1][s + 2 * a[i] + L][3]);
                 if(s + a[i] + L < 2 * L)     add(curr_dp[j][s + L][2] , old_dp[j - 1][s +     a[i] + L][3]);
                  if(s + a[i] + L < 2 * L)    add(curr_dp[j][s + L][1] , old_dp[j - 1][s +     a[i] + L][3]);

            }
        }

       swap(curr_dp , old_dp);
       //memset(curr_dp , 0 , sizeof curr_dp);
    }

    ll ans = 0;

    for(ll s = 0 ; s <= l ; s++)
        add(ans , old_dp[1][s + L][0]);

    cout << ans;
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:101:17: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  101 |                 if(s - a[i] + L >= 0) add(curr_dp[j][s + L][2] , old_dp[j][s - a[i] + L][3]);
      |                 ^~
skyscraper.cpp:102:39: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  102 |                                       add(curr_dp[j][s + L][1] , old_dp[j][s        + L][1]);
      |                                       ^~~
skyscraper.cpp:106:17: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  106 |                 if(s - a[i] + L >= 0) add(curr_dp[j][s + L][0] , old_dp[j][s - a[i] + L][2]);
      |                 ^~
skyscraper.cpp:107:39: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  107 |                                       add(curr_dp[j][s + L][2] , old_dp[j][s        + L][2]);
      |                                       ^~~

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 0 / 80