dave2

from itertools import combinations
from itertools import product


def compute(a,b):
    return abs(a-b)

A = [0,3,3,7,5,3,11,1]

dict = {}
min = A[0]
max = A[0]

for i in range(len(A)):
    if A[i] in dict:
        dict[A[i]].append(i)
    else:
        dict[A[i]] = [i]

    if A[i] < min:
        min = A[i]
    elif A[i] > max:
        max = A[i]


prev = dict[min]
combs = []



for i in range(min+1,max+1,1):
    if i in dict:
        prev.extend(dict[i])
        prev.sort()
        comb = list(combinations(prev, 2))
        combs.extend(comb)
        prev = dict[i]


min = compute(A[combs[0][0]], A[combs[0][1]])

for couple in combs:
    value = compute(A[couple[0]], A[couple[1]])
    if value < min:
        min = value

print(min)