71. Product of Array Except Self

Medium

Topics

Companies

Helpful tools to learn & understand

Visualize LogicActive Simulator

Watch key transitions, pointers, and variables update step-by-step.

Open

Check Solutions

Read clean, documented implementations across multiple patterns.

View Code

Thinkpad (Draw & Note)

Sketch diagrams on an infinite canvas and draft notes directly inline.

Draw

Example 1:

Input: nums = [1,2,3,4]

Output: [24,12,8,6]

Example 2:

Input: nums = [-1,1,0,-3,3]

Output: [0,0,9,0,0]

Constraints:

•
•

Two-pass approach: First pass calculates product of all elements to the left of each index. Second pass calculates product of all elements to the right and multiplies with left products. This avoids division and achieves O(1) space (excluding output array).

Time Complexity

O(n)

Space Complexity

O(1)