Submission #343225

#	Time	Username	Problem	Language	Result	Execution time	Memory
343225		saniyar_krmi	Skyscraper (JOI16_skyscraper)	C++14	100 / 100	206 ms	39276 KiB

skyscraper

// YOt ONLY GOT ONE SHOT
#include <bits/stdc++.h>
#define put(x) cerr << #x << ": " << x << '\n'
#define line() cerr << "**************\n"

//#define F first
//#define S second
//#define mul(x, y) (((x) * (y)) %mod)
//#define bit(i, j) (((i)>>(j)) &1)
//#define left(id) ((id<<1) + 1)
//#define right(id) ((id<<1) + 2)
 
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<pii, int> piii;

const int maxn = 100 + 10, maxA = 1000 + 10, mod = 1e9 + 7;
int n, l;
int a[maxn];
int dp[maxn][maxn][maxA][3];

ll mul(ll a, ll b){
	return (a * b) %mod;
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);  cout.tie(0);

	cin >> n >> l;
	for(int i=0; i<n; i++)
		cin >> a[i];
	sort(a, a+n);

	if(n == 1)
		return cout << "1\n", 0;
	
	for(int i=0; i<=l; i++)
		dp[0][0][i][0] = 1;
	int cost = 0;
	for(int i=1; i<=n; i++)
		for(int j = 1; j <= min(i, (n+1) /2); j++)
			for(int k=0; k<=l; k++)
				for(int m=0; m<3; m++){
					cost = (j * 2 - m) * (a[i] - a[i-1]);
					if(cost > k)
						continue;

					if(m > 0){
						dp[i][j][k][m] += mul(dp[i-1][j][k - cost][m-1], 3 - m);
						dp[i][j][k][m] %= mod;
						if(i + j + 1 - m <= n){
							dp[i][j][k][m] += mul(dp[i-1][j-1][k - cost][m-1], 3 - m);
							dp[i][j][k][m] %= mod;
						}
					}
					if(i + j +1 - m <= n){
						dp[i][j][k][m] += mul(dp[i-1][j-1][k - cost][m], j - m);
						dp[i][j][k][m] %= mod;
						dp[i][j][k][m] += mul(dp[i-1][j][k - cost][m], j * 2 - m);
						dp[i][j][k][m] %= mod;
					}
					if(j < (n + 1) /2){
						dp[i][j][k][m] += mul(dp[i-1][j+1][k - cost][m], j) %mod;
						dp[i][j][k][m] %= mod;
					}
				}

	cout << dp[n][1][l][2] << '\n';
}

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