两两配对差值最小 拼多多[编程题](python AC解)

n = int(input())
l = [int(val) for val in input().split(' ')]
l = sorted(l)
mina = None
maxa = None
for i in range(n//2):
    tempres = l[i] + l[-(i+1)]
    mina = tempres if mina == None else min(mina,tempres)
    maxa = tempres if maxa == None else max(maxa,tempres)
print(maxa-mina)