Skip to main content

Longest Increasing Subsequence

Question​

What is the most efficient algorithm for finding the longest increasing subsequence in a given array of numbers?

Example 1
None

Solution​

all//Longest Increasing Subsequence.py


def longest_increasing_subsequence(sequence):
    longest_sequence = []
    current_sequence = []
    for i in range(len(sequence)):
        if len(current_sequence) == 0 or sequence[i] > current_sequence[-1]:
            current_sequence.append(sequence[i])
            if i == len(sequence) - 1 and len(current_sequence) > len(longest_sequence):
                longest_sequence = current_sequence
        else:
            if len(current_sequence) > len(longest_sequence):
                longest_sequence = current_sequence
            current_sequence = [sequence[i]]
    return longest_sequence

#test
test_sequence = [1, 4, 10, 2, 8, 9, 3, 5, 6]
longest_increasing_subsequence(test_sequence)
# Output: [1, 2, 8, 9]