Package g0801_0900.s0873_length_of_longest_fibonacci_subsequence

Class Solution

java.lang.Object
g0801_0900.s0873_length_of_longest_fibonacci_subsequence.Solution
public class Solution extends java.lang.Object
873 - Length of Longest Fibonacci Subsequence.

Medium

A sequence x1, x2, …, xn is Fibonacci-like if:

  • n >= 3
  • xi + xi+1 == xi+2 for all i + 2 <= n

Given a strictly increasing array arr of positive integers forming a sequence, return the length of the longest Fibonacci-like subsequence of arr. If one does not exist, return 0.

A subsequence is derived from another sequence arr by deleting any number of elements (including none) from arr, without changing the order of the remaining elements. For example, [3, 5, 8] is a subsequence of [3, 4, 5, 6, 7, 8].

Example 1:

Input: arr = [1,2,3,4,5,6,7,8]

Output: 5

Explanation: The longest subsequence that is fibonacci-like: [1,2,3,5,8].

Example 2:

Input: arr = [1,3,7,11,12,14,18]

Output: 3

Explanation: The longest subsequence that is fibonacci-like: [1,11,12], [3,11,14] or [7,11,18].

Constraints:

  • 3 <= arr.length <= 1000
  • 1 <= arr[i] < arr[i + 1] <= 109

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    lenLongestFibSubseq(int[] arr)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • lenLongestFibSubseq

      public int lenLongestFibSubseq(int[] arr)