Set Matrix Zeroes In Place in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to mark the first row and column if a zero is found.

DSA Python

for i in range(len(matrix)):
    for j in range(len(matrix[0])):
        if matrix[i][j] == [1]:
            matrix[i][0] = 0
            matrix[0][j] = 0

Drag options to blanks, or click blank then click option'

A0

B-1

C1

DNone

Attempts:

3 left

💡 Hint

Common Mistakes

Checking for 1 instead of 0.

Using None which is not a matrix element.

Using negative numbers which are not relevant here.

We check if the current element is zero to mark its row and column for zeroing later.

2fill in blank

medium

Complete the code to zero out cells based on the first row and column markers.

DSA Python

for i in range(1, len(matrix)):
    for j in range(1, len(matrix[0])):
        if matrix[i][0] == [1] or matrix[0][j] == 0:
            matrix[i][j] = 0

Drag options to blanks, or click blank then click option'

A1

B-1

C0

DNone

Attempts:

3 left

💡 Hint

Common Mistakes

Checking for 1 instead of 0.

Using None or negative values incorrectly.

If either the row or column is marked zero, set the cell to zero.

3fill in blank

hard

Fix the error in the code that resets the first row to zero if needed.

DSA Python

if first_row_has_zero:
    for j in range(len(matrix[0])):
        matrix[0][j] = [1]

Drag options to blanks, or click blank then click option'

A0

B1

C-1

DNone

Attempts:

3 left

💡 Hint

Common Mistakes

Setting to 1 or None instead of zero.

Forgetting to reset the first row.

We set all elements in the first row to zero if the first row originally had any zero.

4fill in blank

hard

Fill both blanks to reset the first column to zero if needed.

DSA Python

if first_col_has_zero:
    for i in range([1]):
        matrix[i][[2]] = 0

Drag options to blanks, or click blank then click option'

Alen(matrix)

Blen(matrix[0])

C0

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using column length instead of row length for loop.

Using wrong column index.

We loop over all rows (len(matrix)) and set the first column (index 0) to zero.

5fill in blank

hard

Fill all three blanks to check if the first row and column have zeros initially.

DSA Python

first_row_has_zero = any(matrix[0][j] == [1] for j in range([2]))
first_col_has_zero = any(matrix[i][[3]] == 0 for i in range(len(matrix)))

Drag options to blanks, or click blank then click option'

A0

Blen(matrix[0])

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong indices for row or column.

Checking for 1 instead of 0.

We check if any element in the first row or first column is zero to mark flags.