Longest Common Subsequence Length

A subsequence is formed by deleting zero or more elements while preserving the order of the remaining elements. Find the longest length shared by two arrays. Matching elements need not be adjacent. Return only the length, since several equally long subsequences may exist.

Implement longest_common_subsequence_length(first, second).

Input

first: The first sequence.

second: The second sequence.

Output

Return the maximum common subsequence length. If either array is empty, return 0.

Einschränkungen

Each array has 0…1,000 integers between −1,000,000,000 and 1,000,000,000. Duplicates are allowed.

Beispiele

Eingabe:
first = [1, 3, 2, 4]
second = [3, 1, 2, 4]

Erwartete Ausgabe:
expected = 3

Eingabe:
std::vector<long long> first = {1, 3, 2, 4};
std::vector<long long> second = {3, 1, 2, 4};

Erwartete Ausgabe:
long long expected = 3;

Eingabe:
long[] first = new long[] {1, 3, 2, 4};
long[] second = new long[] {3, 1, 2, 4};

Erwartete Ausgabe:
long expected = 3;

Eingabe:
first = [1, 2]
second = [3, 4]

Erwartete Ausgabe:
expected = 0

Eingabe:
std::vector<long long> first = {1, 2};
std::vector<long long> second = {3, 4};

Erwartete Ausgabe:
long long expected = 0;

Eingabe:
long[] first = new long[] {1, 2};
long[] second = new long[] {3, 4};

Erwartete Ausgabe:
long expected = 0;

Referenzen

Diese Aufgabe wurde für CodeUtility angepasst. Beachte die oben genannten Vorgaben und Einschränkungen.

• CSES: Longest Common Subsequence