CF677E.Vanya and Balloons

普及/提高-

通过率:0%

AC君温馨提醒

该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。

题目描述

Vanya plays a game of balloons on the field of size n×nn×n , where each cell contains a balloon with one of the values 00 , 11 , 22 or 33 . The goal is to destroy a cross, such that the product of all values of balloons in the cross is maximum possible. There are two types of crosses: normal and rotated. For example:

<br></br>**o**<br></br>**o**<br></br>ooooo<br></br>**o**<br></br>**o**<br></br>or

<br></br>o***o<br></br>*o*o*<br></br>**o**<br></br>*o*o*<br></br>o***o<br></br>Formally, the cross is given by three integers rr , cc and dd , such that d<=r,c<=nd+1d<=r,c<=n-d+1 . The normal cross consists of balloons located in cells (x,y)(x,y) (where xx stay for the number of the row and yy for the number of the column), such that xryc=0|x-r|·|y-c|=0 and |x-r|+|y-c|<d . Rotated cross consists of balloons located in cells (x,y)(x,y) , such that xr=yc|x-r|=|y-c| and |x-r|<d .

Vanya wants to know the maximum possible product of the values of balls forming one cross. As this value can be large, output it modulo 109+710^{9}+7 .

输入格式

The first line of the input contains a single integer nn ( 1<=n<=10001<=n<=1000 ) — the number of rows and columns in the table with balloons.

The each of the following nn lines contains nn characters '0', '1', '2' or '3' — the description of the values in balloons.

输出格式

Print the maximum possible product modulo 109+710^{9}+7 . Note, that you are not asked to maximize the remainder modulo 109+710^{9}+7 , but to find the maximum value and print it this modulo.

输入输出样例

  • 输入#1

    4
    1233
    0213
    2020
    0303
    

    输出#1

    108
    
  • 输入#2

    5
    00300
    00300
    33333
    00300
    00300
    

    输出#2

    19683
    
  • 输入#3

    5
    00003
    02030
    00300
    03020
    30000
    

    输出#3

    108
    
  • 输入#4

    5
    21312
    10003
    10002
    10003
    23231
    

    输出#4

    3
    
  • 输入#5

    5
    12131
    12111
    12112
    21311
    21212
    

    输出#5

    24
    

说明/提示

In the first sample, the maximum product is achieved for a rotated cross with a center in the cell (3,3)(3,3) and radius 11 : 22333=1082·2·3·3·3=108 .

首页