[LeetCode] Length of Longest Fibonacci Subsequence 最长的斐波那契序列长度

A sequence?X_1, X_2, ..., X_n?is?fibonacci-like?if:

• n >= 3
• X_i + X_{i+1} = X_{i+2}?for all?i + 2 <= n

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

(Recall that a subsequence is derived from another sequence?A?by?deleting any number of?elements (including none)?from?A, 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: [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: [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].

Note:

• 3 <= A.length <= 1000
• 1 <= A[0] < A[1] < ... < A[A.length - 1] <= 10^9
• (The time limit has been reduced by 50% for submissions in Java, C, and C++.)

参考资料：

https://leetcode.com/problems/length-of-longest-fibonacci-subsequence/

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[LeetCode] Length of Longest Fibonacci Subsequence 最长的斐波那契序列长度

原文：https://www.cnblogs.com/grandyang/p/10781190.html