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.

Contraintes

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

Exemples

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

Sortie attendue :
expected = 3

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

Sortie attendue :
long long expected = 3;

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

Sortie attendue :
long expected = 3;

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

Sortie attendue :
expected = 0

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

Sortie attendue :
long long expected = 0;

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

Sortie attendue :
long expected = 0;

Références

Ce défi a été adapté pour CodeUtility. Suivez l'énoncé et les contraintes ci-dessus.

• CSES: Longest Common Subsequence