Submission #891121

#	Time	Username	Problem	Language	Result	Execution time	Memory
891121		thunopro	Maxcomp (info1cup18_maxcomp)	C++14	100 / 100	86 ms	29396 KiB

maxcomp

#include<bits/stdc++.h>
using namespace std ;
#define maxn 1009 
#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 ; 
int a [maxn][maxn] ;

int Min [maxn][maxn][4] ; 

void build () 
{
	memset ( Min , 0x3f , sizeof Min ) ; 
	for ( int i = 1 ; i <= n ; i ++ ) 
	{
		for ( int j = 1 ; j <= m ; j ++ ) 
		{
			Min [i][j][0] = min (Min[i-1][j][0],Min[i][j-1][0]) ; 
			chkmin (Min[i][j][0],a[i][j]-i-j) ; 
		}
	}
	for ( int i = 1 ; i <= n ; i ++ ) 
	{
		for ( int j = m ; j >= 1 ; j -- ) 
		{
			Min [i][j][1] = min (Min[i-1][j][1],Min[i][j+1][1]) ; 
			chkmin (Min[i][j][1],a[i][j]-i+j) ; 
		}
	}
	for ( int i = n ; i >= 1 ; i -- ) 
	{
		for ( int j = 1 ; j <= m ; j ++ ) 
		{
			Min [i][j][2]  = min (Min[i+1][j][2],Min[i][j-1][2]) ; 
			chkmin (Min[i][j][2],a[i][j]+i-j) ; 
		}
	}
	for ( int i = n ; i >= 1 ; i -- ) 
	{
		for ( int j = m ; j >= 1 ; j -- ) 
		{
			Min [i][j][3] = min (Min[i+1][j][3],Min[i][j+1][3]) ; 
			chkmin (Min[i][j][3],a[i][j]+i+j) ; 
		}
	}
	
}
void solve () 
{
	int res = 0 ; 
	for ( int i = 1 ; i <= n ; i ++ ) 
	{
		for ( int j = 1 ; j <= m ; j ++ ) 
		{
			int val = a [i][j] ; 
			// th1 
			chkmax (res,val-i-j-Min[i][j][0]) ; 
			// th2 
			chkmax (res,val-i+j-Min[i][j][1]) ; 
			// th3 
			chkmax (res,val+i-j-Min[i][j][2]) ; 
			// th4 
			chkmax (res,val+i+j-Min[i][j][3]) ; 
			
		}
	}
	cout << res - 1 ; 
}
int main () 
{
	ios_base::sync_with_stdio(0) ; 
	cin.tie(0) ; cout.tie(0) ; 
//	rf () ; 
	cin >> n >> m ; 
	for ( int i = 1 ; i <= n ; i ++ ) for ( int j = 1 ; j <= m ; j ++ ) cin >> a [i][j] ; 
	
	build () ; 
	solve () ; 

}

Compilation message (stderr)

maxcomp.cpp: In function 'void rf()':
maxcomp.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: 15 / 15
• Subtask 2: 15 / 15
• Subtask 3: 30 / 30
• Subtask 4: 40 / 40