Submission #551780

#	Time	Username	Problem	Language	Result	Execution time	Memory
551780		Killer2501	Skyscraper (JOI16_skyscraper)	C++14	100 / 100	1259 ms	189436 KiB

skyscraper

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define ull unsigned long long
#define pb push_back
#define pll pair<int, pii>
#define pii pair<int, int>
#define fi first
#define se second
using namespace std;
const int N = 1e2+5;
const int M = N*100;
const int mod = 1e9+7;
const int base = 75;
const ll inf = 1e12;
int n, t, tong;
int k, m, a[N], b[N], dp[N][N][M][3];
int ans, d[N];
void add(int& x, int y)
{
    x += y;
    if(x >= mod)x -= mod;
}
void sol()
{
    cin >> n >> k;
    for(int i = 1; i <= n; i ++)cin >> a[i], b[i] = i;
    if(n == 1)
    {
        cout << 1 << '\n';
        return;
    }
    sort(a+1, a+1+n);
    reverse(a+1, a+1+n);
    dp[1][1][a[1]*2][0] = 1;
    dp[1][1][a[1]][1] = 2;
    for(int i = 1; i <= n; i ++)
    {
        for(int j = 1; j <= i; j ++)
        {
            for(int p = 0; p < M; p ++)
            {
                for(int q = 0; q < 3; q ++)
                {
                    if(dp[i][j][p][q] == 0)continue;
                    if(p+a[i+1]*2 < M)add(dp[i+1][j+1][p+a[i+1]*2][q], 1ll*dp[i][j][p][q]*(j+1-q)%mod);
                    if(q < 2 && p+a[i+1] < M)add(dp[i+1][j+1][p+a[i+1]][q+1], 1ll*dp[i][j][p][q]*(2-q)%mod);
                    add(dp[i+1][j][p][q], 1ll*dp[i][j][p][q]*(2*j-q)%mod);
                    if(q < 2 && p >= a[i+1])add(dp[i+1][j][p-a[i+1]][q+1], 1ll*dp[i][j][p][q]*(2-q)%mod);
                    if(j > 1 && p >= a[i+1]*2)add(dp[i+1][j-1][p-a[i+1]*2][q], 1ll*dp[i][j][p][q]*(j-1)%mod);
                }
            }
        }
    }
    for(int i = 0; i <= k; i ++)add(ans, dp[n][1][i][2]);
    cout << ans << '\n';
}
int main()
{
    cin.tie(0);
    cout.tie(0);
    ios_base::sync_with_stdio(0);
    #define task "test"
    if(fopen(task".inp", "r"))
	{
		freopen(task".inp", "r", stdin);
		freopen(task".out", "w", stdout);
	}
    int test = 1;
    //cin >> test;
    while(test -- > 0)sol();
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:66:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   66 |   freopen(task".inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:67:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |   freopen(task".out", "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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