Submission #727007

#	Time	Username	Problem	Language	Result	Execution time	Memory
727007		sochu	Skyscraper (JOI16_skyscraper)	C++14	0 / 100	5 ms	1448 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 uint 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 < int , int >
#define pq priority_queue
#define dbg(x) cerr << #x << ": " << x << '\n'

namespace FastRead
{
    char __buff[5000];int __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 int N = 1e2 + 10;
const int L = 1e3 + 10;
const int M = 1e9 + 7;
const ld PI = acos(-1);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int n , l;
int a[N] , dp[N][N][2 * L][4];

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

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

	int i , j , s;

    cin >> n >> l;

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

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

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

    for(i = 2 ; i <= n ; i++)
    {
        for(j = 1 ; j <= i ; j++)
        {
            for(s = -l ; s <= l ; s++)
            {
                ///merge
                if(s - 2 * a[i] + L >= 0)
                {
                    add(dp[i][j][s + L][0] , 1ll * j * dp[i - 1][j + 1][s - 2 * a[i] + L][0]);
                    add(dp[i][j][s + L][1] , 1ll * j * dp[i - 1][j + 1][s - 2 * a[i] + L][1]);
                    add(dp[i][j][s + L][2] , 1ll * j * dp[i - 1][j + 1][s - 2 * a[i] + L][2]);
                    add(dp[i][j][s + L][3] , 1ll * j * dp[i - 1][j + 1][s - 2 * a[i] + L][3]);
                }

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


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

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


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

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

            }
        }
    }

    int ans = 0;

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

    cout << ans;

    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:97:17: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   97 |                 if(s - a[i] + L >= 0) add(dp[i][j][s + L][2] , dp[i - 1][j][s - a[i] + L][3]);
      |                 ^~
skyscraper.cpp:98:39: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   98 |                                       add(dp[i][j][s + L][1] , dp[i - 1][j][s        + L][1]);
      |                                       ^~~
skyscraper.cpp:102:17: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  102 |                 if(s - a[i] + L >= 0) add(dp[i][j][s + L][0] , dp[i - 1][j][s - a[i] + L][2]);
      |                 ^~
skyscraper.cpp:103:39: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  103 |                                       add(dp[i][j][s + L][2] , dp[i - 1][j][s        + L][2]);
      |                                       ^~~

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