Is Find the Minimum Area to Cover All Ones I easy or hard?

The problem is usually classified as Medium difficulty because it requires recognizing that only the extreme coordinates of 1s matter. The implementation itself is straightforward once that insight is clear, involving a single pass over the matrix.

Find the Minimum Area to Cover All Ones I Python/Java solution

The typical Python or Java implementation iterates through the grid using nested loops. Whenever a cell with value 1 is found, update minRow, maxRow, minCol, and maxCol. After traversal, compute the area using the bounding rectangle formula. This implementation runs in O(m*n) time and O(1) space.

How to solve Find the Minimum Area to Cover All Ones I in O(n)?

Treat the grid as m*n cells and perform a single scan. Track the minimum and maximum row and column indices where a 1 appears. After finishing the scan, compute the rectangle area as (maxRow - minRow + 1) * (maxCol - minCol + 1). This linear scan over the matrix achieves O(m*n) time.

What is the best approach for Find the Minimum Area to Cover All Ones I?

The optimal approach scans the grid once and tracks the extreme coordinates where a 1 appears. Maintain minRow, maxRow, minCol, and maxCol while iterating through the matrix. The rectangle defined by these boundaries is the smallest possible area covering all ones. This runs in O(m*n) time and O(1) extra space.

Is Find the Minimum Area to Cover All Ones I asked at Google/Amazon/Meta?

Matrix scanning and bounding box style problems frequently appear in interviews at companies like Amazon, Google, and Meta. The exact problem may vary, but identifying extreme coordinates of elements in a grid is a common pattern tested in array and matrix interview questions.

What data structure is used in Find the Minimum Area to Cover All Ones I?

The solution primarily uses a 2D array (matrix) traversal. Instead of additional data structures, it keeps four integer variables to track the minimum and maximum row and column indices where a 1 occurs.

What is the time complexity of Find the Minimum Area to Cover All Ones I?

The optimal solution runs in O(m*n) time because every cell of the grid is visited exactly once. Only four boundary variables are updated when a 1 is encountered. Space complexity is O(1) since no additional data structures proportional to the grid size are required.

Description Hints 1 Solution Video 12:11

3195. Find the Minimum Area to Cover All Ones I

Medium78.2% acceptance5 companies

You are given a 2D binary array grid. Find a rectangle with horizontal and vertical sides with the smallest area, such that all the 1's in grid lie inside this rectangle.

Return the minimum possible area of the rectangle.

Example 1:

Input: grid = [[0,1,0],[1,0,1]]

Output: 6

Explanation: