Submission #891104

#	Time	Username	Problem	Language	Result	Execution time	Memory
891104		thunopro	Collecting Mushrooms (NOI18_collectmushrooms)	C++14	100 / 100	43 ms	36108 KiB

mushrooms

#include<bits/stdc++.h>
using namespace std ;
#define maxn 500009 
#define ll long long
#define fi first 
#define se second 
#define pb push_back 
#define left id<<1
#define right id<<1|1 
#define re exit(0); 

const int mod = 1e9+7 ; 
const int INF = 1e9 ; 
const int LOG = 18 ; 

typedef vector<int> vi ; 
typedef vector<ll> vl ; 
typedef pair<int,int> pii ; 
typedef vector<pii> vii ; 
typedef pair<ll,ll> pll ;  

void add ( int &a , int b ) 
{
	a += b ; 
	if ( a < 0 ) a += mod ; 
	if ( a >= mod ) a -= mod ; 
}

template < typename T > void chkmin (T &a , T b) { if (a>b) a=b ;} 
template < typename T > void chkmax (T &a , T b) { if (a<b) a=b ;}

void rf () 
{
	freopen ("bai1.inp","r",stdin) ; 
//	freopen ("bai1.out","w",stdout) ; 
}

int _pow ( int a , int n ) 
{
	if ( n == 0 ) return 1 ; 
	int res = _pow(a,n/2) ;
	if ( n % 2 ) return (1ll*res*res%mod*a%mod) ; 
	else return 1ll*res*res%mod ; 
}

int n , m , k , d ; 
vector <char> a [maxn] ; 

const int N = 1e4 + 9 ; 

int bit [N] ; 
vii event [maxn] ; 

void update ( int x , int y ) 
{
	while ( x < N ) bit [x] += y , x += (x&-x) ; 
}
int get ( int x ) 
{
	int res = 0 ; 
	while ( x ) res += bit [x] , x -= (x&-x) ; 
	return res ; 
}

void update ( int l , int r , int w ) 
{
	update (l,w) ; 
	update (r+1,-w) ; 
}

void solve () 
{
	for ( int j = 1 ; j <= m ; j ++ ) 
	{
		for ( int i = 1 ; i <= n ; i ++ ) 
		{
			if ( a [i][j] == 'S' ) 
			{
				int l = max (i-d,1) , r = min (i+d,n) ; 
				int col = max (j-d,1) ; 	
				event [col] . pb ({l,r}) ; 
				col = min (j+d+1,m+1) ; 
				event [col] . pb ({-l,-r}) ; 
			}
		}
	}
	
	int res = 0 ; 
	for ( int j = 1 ; j <= m ; j ++ ) 
	{
		sort (event[j].begin(),event[j].end()) ; 
		for ( auto x : event [j] ) 
		{
			int l = x.fi , r = x.se ; 
			if ( l < 0 ) update (abs(l),abs(r),-1) ; 
			else update (l,r,1) ; 
		}
		for ( int i = 1 ; i <= n ; i ++ ) 
		{
			if ( a [i][j] == 'M' && get (i) >= k ) res ++ ;  
		}
	}
	cout << res ; 
}

int main () 
{
	ios_base::sync_with_stdio(0) ; 
	cin.tie(0) ; cout.tie(0) ; 
//	rf () ; 	
	cin >> n >> m >> d >> k ; 
	if ( n < m ) 
	{
		for ( int i = 1 ; i <= n ; i ++ ) 
		{
			a [i] . resize (m+1) ; 
			for ( int j = 1 ; j <= m ; j ++ ) 
			{
				cin >> a [i][j] ; 
			}
		}
	}
	else 
	{
		for ( int j = 1 ; j <= m ; j ++ ) a [j] . resize (n+1) ; 
		for ( int i = 1 ; i <= n ; i ++ ) 
		{
			for ( int j = 1 ; j <= m ; j ++ ) 
			{
				cin >> a [j][i] ; 
			}
		}
		swap (n,m) ; 
	}
	
	solve () ; 
}

Compilation message (stderr)

mushrooms.cpp: In function 'void rf()':
mushrooms.cpp:34:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |  freopen ("bai1.inp","r",stdin) ;
      |  ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 10 / 10
• Subtask 3: 18 / 18
• Subtask 4: 23 / 23
• Subtask 5: 19 / 19
• Subtask 6: 21 / 21