arrays Archives - Page 2 of 14

Mathematical explanation of Leetcode question: Container With Most Water

August 23, 2022 by Magenaut

I was working on a medium level leetcode question 11. Container With Most Water. Besides the brute force solution with O(n^2), there is an optimal solution with complexity of O(n) by using two pointers from left and right side of the container. I am a little bit confused why this “two pointers” method must include the optimal solution. Does anyone know how to prove the correctness of this algorithm mathematically? This is an algorithm that I don’t know of. Thank you!

All possible combinations in a binary image

August 23, 2022 by Magenaut

I’m trying to create all possible combinations of 0 and 1 in an array that have the shape (n, 10). For example, if we assume an arbitrary combination like this: np.array([0, 0, 1, 1, 0, 0, 1, 1, 0, 0]), how can I generate all possible combinations (which will result in 2^10=1024 arrays)?

Find match of numeric arrays Python

August 23, 2022 by Magenaut

Consider I have 2 arrays. arr2 will always be longer than arr1. I’d like to drop the values from arr2 to best fit arr1. If arr2 doesn’t have an equal value to arr1 it will need to be the closest value that is still in arr2.

how to calculate Manhattan distance (or L1/ cityblock) for two 2D array?

August 22, 2022 by Magenaut

For 1D vector/array it’s easier. For example:

Python for loop multi-dimensional array indexing issue

August 22, 2022 by Magenaut

I have the first two strings in a string list strs that is guaranteed to have length of at least 2. I want to compare their letters against each other, and perform a task when their letters are identical. Here is the code I am using:

Create a new array of all values from an array with step

August 22, 2022 by Magenaut

I am new to Python. I would like to create a new array, that contains all values from an existing array with the step.

NumPy array row differences

August 22, 2022 by Magenaut

I have a NumPy array vectors = np.random.randn(rows, cols). I want to find differences between its rows according to some other array diffs which is sparse and “2-hot”: containing a 1 in its column corresponding to the first row of vectors and a -1 corresponding to the second row. Perhaps an example shall make it clearer:

numpy “insert” does not insert anything

August 22, 2022 by Magenaut

I have issues with the Numpy python library in inserting date to the array. Here is the code that I have a problem with:

Creating 1D array from two 1D arrays with condition

August 22, 2022 by Magenaut

I am running this program: