#0281

Maximal Square

MediumDSA28 min20 XP

Problem

Given a matrix of "0" and "1" strings, return the area of the largest square made only of 1s.

Why This Matters

Maximal Square is a great 2D DP example because every cell depends on three neighbors.

Function Signature

def maximal_square(matrix):

Examples

Example 1

Inputmatrix = [["1","0","1","0"],["1","1","1","1"],["1","1","1","1"]]

Output4

The largest all-1 square has side length 2, so area is 4.

Constraints

Return the exact requested value.
Handle edge cases cleanly.
Use the intended DSA pattern when brute force would scale poorly.

CodePython

def maximal_square(matrix):
    """
    Input example: matrix = [["1","0","1","0"],["1","1","1","1"],["1","1","1","1"]]
    Return: 4
    For pattern problems, return a list of rows. Do not print the rows.
    """
    # write your code here
    return 0

def maximal_square(matrix):
    """
    Input example: matrix = [["1","0","1","0"],["1","1","1","1"],["1","1","1","1"]]
    Return: 4
    For pattern problems, return a list of rows. Do not print the rows.
    """
    # write your code here
    return 0

Visible browser tests run here when available.

Testcases2 visible / 3 hidden categories

Two by two square

Inputmatrix with side 2

Expected4

The largest square side is 2.

No ones

Input[["0","0"]]

Expected0

No square of 1s exists.

Hidden Test Categories

single cell onesingle rowlarger square