TopCoder problem "SquareOfDigits" used in SRM 439 (Division II Level One)

Problem Statement

You are given a String[] data representing a rectangular grid where each cell contains a digit. Find the largest square in this grid that contains the same digit in all of its corner cells. The sides of the square must be parallel to the sides of the grid. If there is more than one such largest square, pick any one of them.

Return the number of cells in the square. Note that a single cell is also considered a square, so there will always be an answer.

Definition

Class:	SquareOfDigits
Method:	getMax
Parameters:	String[]
Returns:	int
Method signature:	int getMax(String[] data)
(be sure your method is public)

Constraints

data will contain between 1 and 50 elements, inclusive.

Each element of data will contain between 1 and 50 digits ('0'-'9'), inclusive.

All elements of data will have the same length.

Examples

{"12",
 "34"}

Returns: 1

All digits in the grid are different, so the biggest feasible square has only one cell.

{"1255",
 "3455"}

Returns: 4

Four '5' digits form a feasible square.

{"42101",
 "22100",
 "22101"}

Returns: 9

The largest square here is the 3 x 3 square that contains the digit '1' in each of its corner cells.

{"1234567890"}

Returns: 1

{"9785409507",
 "2055103694",
 "0861396761",
 "3073207669",
 "1233049493",
 "2300248968",
 "9769239548",
 "7984130001",
 "1670020095",
 "8894239889",
 "4053971072"}

Returns: 49

Problem url:

http://www.topcoder.com/stat?c=problem_statement&pm=10395

Problem stats url:

http://www.topcoder.com/tc?module=ProblemDetail&rd=13747&pm=10395

Writer:

it4.kp

Testers:

PabloGilberto , Andrew_Lazarev , ivan_metelsky

Problem categories:

Brute Force