Is Find the Width of Columns of a Grid easy or hard?

Find the Width of Columns of a Grid is an easy-level problem. It focuses on basic matrix traversal, simple comparisons, and handling integer formatting edge cases such as negative numbers.

Find the Width of Columns of a Grid Python/Java solution

In Python or Java, iterate over each column and check every element in that column. Convert the integer to a string (or compute digit length) and track the maximum length. Store that maximum in the result array for the column.

How to solve Find the Width of Columns of a Grid in O(n)?

The full grid must be inspected, so the overall complexity is O(m*n). You achieve this by scanning column by column and updating the maximum character length for each column. Each element contributes a constant-time width calculation.

What is the best approach for Find the Width of Columns of a Grid?

The most practical approach is column-wise iteration. For each column, scan all rows and compute the length of each number’s string representation, keeping the maximum. This runs in O(m*n) time and uses O(n) space for the result array.

Is Find the Width of Columns of a Grid asked at Google/Amazon/Meta?

This problem is categorized as an easy matrix traversal question similar to those asked in screening rounds at companies like Amazon and Google. It tests basic array and matrix iteration along with attention to detail when formatting integers.

What data structure is used in Find the Width of Columns of a Grid?

The solution primarily uses arrays and a matrix. The input is a 2D grid, and the output is a one-dimensional array storing the maximum width for each column.

What is the time complexity of Find the Width of Columns of a Grid?

The time complexity is O(m*n), where m is the number of rows and n is the number of columns. Each grid element is visited exactly once to determine its formatted length. The space complexity is O(n) for storing the width of each column.

Description Hints 2 Solution Video 2:49

2639. Find the Width of Columns of a Grid

Easy71.0% acceptance2 companies

You are given a 0-indexed m x n integer matrix grid. The width of a column is the maximum length of its integers.

For example, if grid = [[-10], [3], [12]], the width of the only column is 3 since -10 is of length 3.

Return an integer array ans of size n where ans[i] is the width of the i^th column.

The length of an integer x with len digits is equal to len if x is non-negative, and len + 1 otherwise.

Example 1:

Input: grid = [[1],[22],[333]]
Output: [3]
Explanation: In the 0^th column, 333 is of length 3.

Example 2:

Input: grid = [[-15,1,3],[15,7,12],[5,6,-2]]
Output: [3,1,2]
Explanation: 
In the 0^th column, only -15 is of length 3.
In the 1^st column, all integers are of length 1. 
In the 2^nd column, both 12 and -2 are of length 2.

Constraints:

m == grid.length
n == grid[i].length
1 <= m, n <= 100
-10⁹ <= grid[r][c] <= 10⁹

Asked at 2 companies

Samsung Atlassian

Topics

Array Matrix

Hints open one at a time

Hint 1

You can find the length of a number by dividing it by 10 and then rounding it down again and again until this number becomes equal to 0. Add 1 if this number is negative.

Hint 2

Traverse the matrix column-wise to find the maximum length in each column.

2:49

Still stuck?Read 3 approaches, or watch a walkthrough.

Open solution