Minkowski sum image from Project Rosalind.

This problem asks:

Given: Two multisets of positive real numbers S1 and S2.

Return: The largest multiplicity of S1⊖S2, as well as the absolute value of the number x maximizing (S1⊖S2)(x)

References

Restating the problem

Given two multisets, I need to find the value that appears most often in their multiset difference. Then, I need to find the absolute value of the greatest multiset difference between the two multisets.

Solution steps

First, I wrote a mink_diff function with these nested loops:

def mink_diff(S1, S2):
    result = []
    for s1 in S1:
        for s2 in S2:
            result.append(round(s1 - s2, 5))
    return result

Then, I wrote this function to find the maximum multiplicty in a given multiset with:

def max_multiplicity(mylist):
    item = max(mylist, key=mylist.count)
    return mylist.count(item)

Finally, I wrote this function to find the most common absolute value in a multiset:

def max_diff(mylist):
    newlist = []
    for item in mylist:
        newlist.append(abs(item))
    return max(newlist, key=newlist.count)

These three functions combined to give the correct response for the sample dataset. When I downloaded a real dataset from Project Rosalind, the site crashed when I submitted my response.

A few minutes later, I tried again and got a correct result response. I spent about 60 minutes on this challenge. 1,162 people solved this before me. This is my 61st correct response.