CODEWITHSUNDEEP
pythonlist
Vandit
Vandit

Reputation: 109

Largest distance in an integer list

How to find the maximum distance between two same elements/integers of a list in python. e.g. if a list is [1,3,3,5,6,4,8,6,0,3,5] Output would be 8 (distance b/w 3's is maximum here)

Upvotes: 3

Views: 378

Answers (2)

kuzand
kuzand

Reputation: 9806

Using numpy (slower than abc's solution):

import numpy as np

L = [1,3,3,5,6,4,8,6,0,3,5]
x, y = np.meshgrid(L, L)
w = np.where(x == y)
max_dist = np.max(w[1] - w[0])

Upvotes: 0

abc
abc

Reputation: 11939

You can use a dictionary where for each value you save the indices.

from collections import defaultdict

d = defaultdict(list)

for i,el in enumerate(l):
    d[el].append(i)

max_dist = max(d[k][-1]-d[k][0] for k in d)

Upvotes: 3

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