CODEWITHSUNDEEP
pythonpython-3.x
user398843
user398843

Reputation: 191

Compare two lists recursively

Suppose we have v1 = list("abcdabcd") and v2 = list("caabccab"), where a corresponds to c, and b corresponds to d. Note that the list() has separated strings into a list of singletons.

How can we use recursion to find out the longest pair(s), where a pair means, for example, that cda and abc in this case.

Upvotes: 0

Views: 387

Answers (1)

Alec
Alec

Reputation: 9575

You can iterate through and detect matches:

v1 = list("abcdabcd")
v2 = list("caabccab")

def longest_match(v1, v2):
    consecutive, max_c, max_m1, max_m2 = [0]*4
    match1, match2 = '', ''
    a, b, c, d = 'a', 'b', 'c', 'd'
    for i in range(len(v1)):
        if (v1[i] == a and v2[i] == c) or (v1[i] == c and v2[i] == a) or (v1[i] == b and v2[i] == d) or (v1[i] == d and v2[i] == b):
            consecutive += 1
            match1 += v1[i]
            match2 += v2[i]
        else:
            if consecutive > max_c:
                max_c = consecutive
                max_m1, max_m2 = match1, match2
            consecutive, match1, match2 = 0, '', ''

    match = (max_m1, max_m2)

    return max_c, match

print(longest_match(v1, v2)[1])  # ('cda', 'abc')

Upvotes: 1

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