Find elements' indices with maximum difference between two lists-CodePudding

There are two lists

l1 = [1, 2.3, 1.4, 1.1]

l2 = [2.1, 0.9, 1.1, 3.2]

and I want to find the elements in the lists that have the maximum difference between the lists.

I.e.:

l1 = [1, 2.3, 1.4, 1.1] should return 0 for index 0 of the smallest number

l2 = [2.1, 0.9, 1.1, 3.2] should return 3 for index 3 of the highest number

CodePudding user response：

Try this:

l1 = [1, 2.3, 1.4, 1.1]
l2 = [2.1, 0.9, 1.1, 3.2]


def max_diff(l1, l2):
    min_l1 = min(l1)
    max_l1 = max(l1)
    min_l2 = min(l2)
    max_l2 = max(l2)
    max_diff1 = max_l2 - min_l1
    max_diff2 = max_l1 - min_l2
    if max_diff1 > max_diff2:
        return l1.index(min_l1), l2.index(max_l2), max_diff1
    else:
        return l1.index(max_l1), l2.index(min_l2), max_diff2


l1_index, l2_index, max_diff = max_diff(l1, l2)
print(l1_index, l2_index, max_diff)  # 0 3 2.2

Note that this computes the max difference and can return either the (min(l1), max(l2)) or (max(l1), min(l2)) depending on the items in the list.

CodePudding user response：

In case there are multiple results:

l1 = [1, 2.3, 3.2, 1]
l2 = [1, 1, 1.1, 3.2]


def find_all(list1, list2):
    def return_all(func, lst):
        return [pos for pos, val in enumerate(lst) if val == func(lst)]
    return [return_all(max, list1), return_all(min, list2)]


def output(res, order):
    print(f"max position list {order[0]}: {res[order[0] - 1]}")
    print(f"min position list {order[1]}: {res[order[1] - 1]}")


if max(l1) - min(l2) > max(l2) - min(l1):
    results = find_all(l1, l2)
    output(results, (1, 2))
elif max(l1) - min(l2) < max(l2) - min(l1):
    results = find_all(l2, l1)
    output(results[::-1], (2, 1))
else:
    results = find_all(l1, l2)
    output(results, (1, 2))
    print ('And:')
    results = find_all(l2, l1)
    output(results[::-1], (2, 1))

output:

    max position list 1: [2]
    min position list 2: [0, 1]
    And:
    max position list 2: [3]
    min position list 1: [0, 3]

CodePudding user response：

Here's a more concise approach:

l1 = [1, 2.3, 1.4, 1.1]
l2 = [2.1, 0.9, 1.1, 3.2]

for k, v in {min: ['lo', l1], max: ['hi', l2]}.items():
    print(f'{v[0]}={k(range(len(v[1])), key=v[1].__getitem__)}')

Output:

lo=0
hi=3