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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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: N=len(A) index={} for i in range(N): index[A[i]]=i dp=[[0]*N for _ in range(N)] ans=0 for i in range(N-1,-1,-1): hi=A[i] for j in range(i-1,-1,-1): lo=A[j] if hi-lo<=0 or hi-lo>=lo: break if hi-lo in index: ind = index[hi-lo] length = 1+dp[j][i] dp[ind][j]=length ans=max(ans,length) return ans+2 if ans>0 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: mp = {} for v in A: mp[v] = set() result = 0 for i in range(len(A)): for j in range(i + 1, len(A)): a = A[i] b = A[j] l = 2 while True: if b in mp[a]: break if l != 2: mp[a].add(b) c = a + b if c not in mp: break a, b = b, c l += 1 if l < 3: l = 0 else: result = max(result, l) return result
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: index = {x: i for i, x in enumerate(A)} longest = [[2 for i in range(len(A))] for j in range(len(A))] ans = 0 for k, z in enumerate(A): for j in range(k): i = index.get(z - A[j], None) if i is not None and i < j: longest[j][k] = longest[i][j] + 1 ans = max(ans, longest[j][k]) return ans if ans >=3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: s = set(A) d = dict() for i in range(2, len(A)): for j in range(i): if A[i] < 2 * A[j] and A[i] - A[j] in s: d[(A[i], A[j])] = d.get((A[j], A[i]-A[j]), 2) + 1 return max(d.values() or [0])
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: s = set(A) n = len(A) def getlength(a, b): l = 0 temp = a + b if temp in s: l = 2 else: return 0 while temp in s: temp, b = temp + b, temp l += 1 return l mx = 0 for i in range(n): for j in range(i+1, n): ll = getlength(A[i], A[j]) if mx < ll: mx = ll return mx
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: Aset = set(A) res = 0 for i in range(len(A)-1): for j in range(i+1, len(A)): a, b = A[i], A[j] temp = 2 while a+b in Aset: temp += 1 a, b = b, a+b if temp >= 3: res = max(res, temp) return res
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: n = len(A) dp = [{} for i in range(n)] result = 0 for i in range(n): for j in range(i): prev = A[i] - A[j] if prev in dp[j]: l = dp[i][A[j]] = dp[j][prev] + 1 result = max(result, l) else: dp[i][A[j]] = 2 return result
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: L = len(A) res = 0 if L<3: return 0 if L==3: return 3 if A[0]+A[1]==A[2] else 0 s = set(A) for i in range(2,L): for j in range(i): L,R = A[j],A[i] cur = 2 while R-L in s and R-L<L: cur += 1 L,R = R-L,L res = max(res,cur) #print(A[i],A[j],cur) return res if res>2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: set_a = set(A) res = 0 for i in range(len(A)): for j in range(i+1, len(A)): x, y = A[i], A[j] leng = 2 while x+y in set_a: x, y = y, x+y leng += 1 res = max(res, leng) return res if res >=3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: s = set(A) res = 2 for i in range(len(A)): for j in range(i + 1, len(A)): a = A[i] b = A[j] lengthOfSeq = 2 while a + b in s: a, b, lengthOfSeq = b, a + b, lengthOfSeq + 1 res = max(res,lengthOfSeq) return res if res > 2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: n = len(A) dp = [[2] * n for i in range(n)] m = dict() for i in range(n): m[A[i]] = i ans = 0 for i in range(n): for j in range(i+1, n): a_k = A[j] - A[i] if a_k > A[i]: break k = m.get(a_k, None) if k is not None and k < i: dp[i][j] = dp[k][i] + 1 ans = max(ans, dp[i][j]) return ans if ans >= 3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: n = len(A) max_ = 0 dp = [[0 for i in range(n)] for j in range(n)] for i in range(2, n): l = 0 r = i - 1 while l < r: sum_ = A[l] + A[r] if sum_ > A[i]: r -= 1 elif sum_ < A[i]: l += 1 else: dp[r][i] = dp[l][r] + 1 max_ = max(max_, dp[r][i]) r -= 1 l += 1 if max_ == 0: return 0 else: return max_ + 2
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: n = len(A) dp = [[2 for _ in range(n)] for _ in range(n)] indMap = {x: i for i, x in enumerate(A)} for i in range(n): for j in range(i+1, n): diff = A[j] - A[i] if diff in indMap and indMap[diff] < i: k = indMap[diff] dp[i][j] = max(dp[i][j], 1 + dp[k][i]) return max([v for row in dp for v in row if v > 2] or [0])
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: s = set(A) res = 2 for i in range(len(A)): for j in range(i + 1, len(A)): a, b, l = A[i], A[j], 2 while a + b in s: a, b, l = b, a + b, l + 1 res = max(res, l) return res if res > 2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: S = set(A) i = 0 max_len = 0 while i < len(A)-1: j = i + 1 while j < len(A): subSeq = [A[i], A[j]] while subSeq[-1] + subSeq[-2] in S: subSeq.append(subSeq[-1]+subSeq[-2]) # print(subSeq) if len(subSeq) > max_len: max_len = len(subSeq) j += 1 i += 1 return max_len
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: n = len(A) s = set(A) res = 2 for i in range(n): for j in range(i+1, n): a, b, l = A[i], A[j], 2 while a+b in s: a,b,l = b,a+b,l+1 res = max(res, l) return res if res > 2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: n = len(A) dp = [[2 for _ in range(n)] for _ in range(n)] indMap = {x: i for i, x in enumerate(A)} for i in range(n): for j in range(i+1, n): diff = A[j] - A[i] if diff in indMap and indMap[diff] < i: k = indMap[diff] dp[i][j] = max(dp[i][j], 1 + dp[k][i]) res = 0 for row in dp: for v in row: if v > 2: res = max(res, v) return res
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: d={} for i in range(len(A)): d[A[i]]=i ans=0 for i in range(0,len(A)): for j in range(i+1,len(A)): y=A[i]+A[j] x=A[j] l=2 while y in d and d[y]>j: # print(y,l) z=x+y x=y y=z l+=1 ans=max(ans,l) return ans if ans>=3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: sA = set(A) B = Counter() ans = 0 for i in reversed(range(len(A))): a = A[i] for b in A[i+1:]: c = a + b if c in sA: B[a, b] = B[b, c] + 1 # if recording B[b,c], everything is counted 1. We are tracking back like 3+5, 2+3, 1+2. So we want the 1+2 to be counted the most. ans = max(ans, B[a, b] + 2) # [a, b, c] = [1 ,2, 3], B[b, c] = 1 if c > A[-1]: break # the inner loop needn't continue return ans if ans >= 3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: res = 0 A_dict = {} for x in A: A_dict[x] = A_dict.get(x,0) + 1 for i in range(len(A)-1): for j in range(i+1, len(A)): a, b = A[i], A[j] c = a + b length = 0 while c in A_dict: length += 1 a, b = b, c c = a + b res = max(res, length) return res + 2 if res > 0 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: ans = 0 setA = set(A) for i in range(len(A)): for j in range(i+1, len(A)): temp = 2 x = A[j] y = A[i] + A[j] while y in setA: temp += 1 x, y = y, x+y ans = max(ans, temp) return ans if ans >= 3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: ''' correct but too slow lol :'( l = len(A) def loop(one: int, two: int, ind: int, length: int) -> int: if (ind == l): return length elif (one + two == A[ind]): #print(\"one, two are \" + str(one) + \" \" + str(two)) return loop(two, A[ind], ind + 1, length + 1) else: return loop(one, two, ind + 1, length) maxLen = 0 for i in range(l): for j in range(i+1, l): c = loop(A[i], A[j], j+1, 0) maxLen = max(maxLen, c) return (maxLen + 2) if maxLen else maxLen ''' mySet = set(A) maxCount = 0 l = len(A) for i in range(l): for j in range(i+1, l): one = A[i] two = A[j] count = 0 while(one + two) in mySet: temp = two two = one + two one = temp count += 1 maxCount = max(maxCount, count) return maxCount + 2 if maxCount else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: max_length = 0 S = set(A) for i in range(len(A)): for j in range(i+1, len(A)): x, y = A[i], A[j] expected = x+y length = 2 while expected in S: x=y y=expected expected = x+y length += 1 max_length = max(max_length, length) return max_length if max_length >= 3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: s = set(A) res = 2 for i in range(len(A)): for j in range(i + 1,len(A)): a = A[i] b = A[j] l = 2 while a + b in s: a,b,l = b,a + b,l + 1 res = max(res,l) % (10 ** 9 + 7) return res if res > 2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: res = 0 A_dict = {} for x in A: A_dict[x] = A_dict.get(x,0) + 1 for i in range(len(A)-1): for j in range(i+1, len(A)): a, b = A[i], A[j] # loop all initial candidates c = a + b length = 0 while c in A_dict: length += 1 a, b = b, c c = a + b res = max(res, length) return res + 2 if res > 0 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: def getLength(orgprev,orgcurr,prev,curr): nxt = curr+prev if nxt in Aset: return 1+getLength(orgprev,orgcurr,curr,nxt) else: return 2 if orgprev != prev and orgcurr != curr else 0 Aset = set(A) return max(max([getLength(a,b,a,b) for a in A[:i]],default=float('-inf')) for i,b in enumerate(A))
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: s = set(A) dp = defaultdict(int) ans = 0 for i in range(len(A)): for j in range(i+1, len(A)): prev, curr, l = A[i], A[j], 0 while prev + curr in s: l += 1 dp[prev+curr] = l prev, curr = curr, prev + curr ans = max(ans, l) return ans + 2 if ans > 0 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A): s = set(A) res = 2 for i in range(len(A)): for j in range(i + 1, len(A)): a, b, l = A[i], A[j], 2 while a + b in s: a, b, l = b, a + b, l + 1 res = max(res, l) return res if res > 2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: index = {x:i for i, x in enumerate(A)} longest = collections.defaultdict(lambda: 2) result = 0 for k, z in enumerate(A): for j in range(k): i = index.get(z-A[j], float('inf')) if i < j: longest[j, k] = longest[i, j] + 1 if longest[j, k] > result: result = longest[j, k] return result if result >= 3 else 0
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++.)
class Solution(object): def lenLongestFibSubseq(self, A): S = set(A) ans = 0 for i in range(len(A)): for j in range(i+1, len(A)): x, y = A[j], A[i] + A[j] length = 2 while y in S: x, y = y, x + y length += 1 ans = max(ans, length) return ans if ans >= 3 else 0
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++.)
class Solution: def new_lenLongestFibSubseq(self, A: List[int]) -> int: exists = set(A) max_length = 2 for i in range(len(A)): first = A[i] for j in range(i): second = A[j] start = second curr_length = 2 while (first + second) in exists: curr_length += 1 curr = first + second second = first first = curr max_length = max(max_length, curr_length) if max_length < 3: return 0 return max_length def lenLongestFibSubseq(self, A: List[int]) -> int: exists = set(A) max_length = 2 for i in range(len(A)): for j in range(i): b = A[i] a = A[j] curr_length = 2 while (a + b) in exists: curr_length += 1 curr = a + b a = b b = curr max_length = max(max_length, curr_length) if max_length <= 2: return 0 return max_length # [1,2,3,4,5,6,7,8] # # **** START == 1 **** # # second = 1 # first = 2 # curr_length = 3 # curr = 3 # cache[1] = max(cache[1]+1, 3) # cache[1] = max(0+1, 3) # cache[1] = 3 # # second = 2 # first = 3 # curr_length = 4 # curr = 5 # # cache[1] = max(cache[1], curr_length) # cache[1] = max(3, 3) # cache[1] = 4 # # second = 3 # first = 5 # curr_length = 5 # curr = 8 # # cache[1] = max(cache[1], 5) # cache[1] = 5 # # second = 5 # first = 8 # curr_length = 6 # curr = 13 # # 13 not in A, next pair # # # **** START == 1 **** # # second = 1 # first = 3 # curr_length = 3 # curr = 4 # # cache[1] = max(5, 3) # cache[1] = 5 # # second = 3 # first = 4 # curr = 7 # curr_length = 4 # # cache[1] = max(5, 4) # cache[1] = 5 # # second = 4 # first = 7 # curr = 11 # # 11 not in A, exit #
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: res=0 d={x:i for i,x in enumerate(A)} n=len(A) dp=[[2 for j in range(n)] for i in range(n)] for i in range(2,n): for j in range(i): z=A[i] x=A[j] y=z-x k=d.get(y,-1) #x<y<z if x<y and k!=-1: dp[i][k]=1+dp[k][j] res=max(res,dp[i][k]) if res>2: return res return 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: S = set(A) ans = 0 for i in range(len(A)): for j in range(i+1, len(A)): x, y = A[j], A[i] + A[j] length = 2 while y in S: x, y = y, x + y length += 1 ans = max(ans, length) return ans if ans >= 3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: if len(A) < 3: return 0 S = set(A) ans = 0 for i in range(len(A) - 1): for j in range(i + 1, len(A)): l = 2 x, y = A[j], A[i] + A[j] while y in S: l += 1 x, y = y, x + y ans = max(ans, l) return ans if ans >= 3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: exists = set(A) max_length = 2 for i in range(len(A)): for j in range(i+1, len(A)): a = A[i] b = A[j] curr_length = 2 while (a + b) in exists: curr_length += 1 #curr = a + b #a = b #b = curr a, b = b, a + b max_length = max(max_length, curr_length) if max_length <= 2: return 0 return max_length # [1,2,3,4,5,6,7,8] # # **** START == 1 **** # # second = 1 # first = 2 # curr_length = 3 # curr = 3 # cache[1] = max(cache[1]+1, 3) # cache[1] = max(0+1, 3) # cache[1] = 3 # # second = 2 # first = 3 # curr_length = 4 # curr = 5 # # cache[1] = max(cache[1], curr_length) # cache[1] = max(3, 3) # cache[1] = 4 # # second = 3 # first = 5 # curr_length = 5 # curr = 8 # # cache[1] = max(cache[1], 5) # cache[1] = 5 # # second = 5 # first = 8 # curr_length = 6 # curr = 13 # # 13 not in A, next pair # # # **** START == 1 **** # # second = 1 # first = 3 # curr_length = 3 # curr = 4 # # cache[1] = max(5, 3) # cache[1] = 5 # # second = 3 # first = 4 # curr = 7 # curr_length = 4 # # cache[1] = max(5, 4) # cache[1] = 5 # # second = 4 # first = 7 # curr = 11 # # 11 not in A, exit #
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: S = set(A) ans = 0 for i in range(len(A)): for j in range(i + 1, len(A)): x, y = A[j], A[i] + A[j] length = 2 while y in S: x, y = y, x + y length += 1 ans = max(ans, length) return ans if ans >= 3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: indexes={A[i]:i for i in range(len(A))} dp=[[2 for i in range(len(A))] for j in range(len(A))] z=0 for i in range(1,len(A)): for j in range(0,i): idx=indexes.get(A[i]+A[j],-1) if idx==-1: continue else: dp[i][idx]=dp[j][i]+1 z=max(max(dp[i]),z) if z<3: return 0 return z
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: set_val = set(A) max_len = 0 for i in range(len(A)): for j in range(i+1, len(A)): p2, p1 = A[i],A[j] cnt = 0 while p2 + p1 in set_val: z = p2 + p1 p2 = p1 p1 = z cnt += 1 max_len = max(max_len, cnt + 2 if cnt > 0 else cnt) return max_len
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: if len(A) == 0: return A result = 0 aref = set(A) for i in range(len(A)): for j in range(i+1, len(A)): x, y = A[j], A[i] + A[j] seq_length = 0 while y in aref: if seq_length == 0: seq_length = 2 seq_length += 1 x, y = y, x+y result = max(result,seq_length) return result
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: s = set(A) res = 2 for i in range(len(A)): for j in range(i+1,len(A)): a = A[i] b = A[j] l = 2 while a + b in s: a,b,l = b,a + b,l + 1 res = max(res,l) % (10 ** 9 + 7) return res if res > 2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: mapA = {n: i for i, n in enumerate(A)} # 1. Brutal Force l = ans = 0 for i in range(len(A)): for j in range(i+1, len(A)): x, y = A[j], A[i] + A[j] l = 2 while y in mapA: x, y = y, x + y l += 1 ans = max(ans, l) return ans if ans >= 3 else 0
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++.)
from collections import defaultdict class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: # [1,2,3,4,5,6,7,8] # [0,0,3,] memo = defaultdict(int) visited = dict() visited[A[0]] = True visited[A[1]] = True ret = 0 for i in range(2, len(A)): num = A[i] visited[num] = True for j in range(i - 1, -1, -1): if num - A[j] in visited and num - A[j] < A[j]: old_key = (num - A[j], A[j]) val = memo[old_key] + 1 ret = max(ret, val) key = (A[j], num) # print(old_key) # print(key, val) # print('-----') memo[key] = val if ret: ret += 2 return ret
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: longest = 0 coll = set(A) n = len(A) lookup = [[None for _ in range(n)] for _ in range(n)] for i in range(n - 2): for j in range(i + 1, n - 1): target = A[i] + A[j] prev = A[j] while target in coll: if lookup[i][j]: lookup[i][j] += 1 else: lookup[i][j] = 3 temp = target target += prev prev = temp longest = max(longest, lookup[i][j]) return longest
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: s = set(A) n = len(A) result = 0 for i in range(n-1): for j in range(i+1, n): a, b = A[i], A[j] count = 2 while a+b in s: a, b = b, a+b count += 1 result = max(result, count) return result if result > 2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: S = set(A) n = len(A) res = 0 for i in range(n): for j in range(i+1,n): x, y = A[j],A[i] + A[j] ans = 2 while y in S: x, y = y, x + y ans += 1 res = max(res, ans) return res if res >= 3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: s = set(A) res = 2 for i in range(len(A)): for j in range(i + 1,len(A)): a = A[i] b = A[j] l = 2 while a + b in s: a,b,l = b,a + b,l + 1 res = max(res,l) % (10 ** 9 + 7) return res if res > 2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: n, s, res = len(A), set(A), 0 for i in range(n): for j in range(i+1, n): x, y, l = A[j], A[i] + A[j], 2 while y in s: x, y = y, x + y l += 1 res = max(res, l) return res if res > 2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: exists = set(A) max_length = 2 for i in range(len(A)): for j in range(i): first = A[i] second = A[j] start = second curr_length = 2 while (first + second) in exists: curr_length += 1 curr = first + second second = first first = curr max_length = max(max_length, curr_length) if max_length < 3: return 0 return max_length def old_lenLongestFibSubseq(self, A: List[int]) -> int: exists = set(A) max_length = 2 for i in range(len(A)): for j in range(i): b = A[i] a = A[j] curr_length = 2 while (a + b) in exists: curr_length += 1 curr = a + b a = b b = curr max_length = max(max_length, curr_length) if max_length <= 2: return 0 return max_length # [1,2,3,4,5,6,7,8] # # **** START == 1 **** # # second = 1 # first = 2 # curr_length = 3 # curr = 3 # cache[1] = max(cache[1]+1, 3) # cache[1] = max(0+1, 3) # cache[1] = 3 # # second = 2 # first = 3 # curr_length = 4 # curr = 5 # # cache[1] = max(cache[1], curr_length) # cache[1] = max(3, 3) # cache[1] = 4 # # second = 3 # first = 5 # curr_length = 5 # curr = 8 # # cache[1] = max(cache[1], 5) # cache[1] = 5 # # second = 5 # first = 8 # curr_length = 6 # curr = 13 # # 13 not in A, next pair # # # **** START == 1 **** # # second = 1 # first = 3 # curr_length = 3 # curr = 4 # # cache[1] = max(5, 3) # cache[1] = 5 # # second = 3 # first = 4 # curr = 7 # curr_length = 4 # # cache[1] = max(5, 4) # cache[1] = 5 # # second = 4 # first = 7 # curr = 11 # # 11 not in A, exit #
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: d1={x:i for i,x in enumerate(A)} d2={} ans=0 for i in range(1,len(A)): for j in range(i): d2[(j,i)]=2 val= A[i]-A[j] if(val in d1 and d1[val]<j): d2[(j,i)]=d2[(d1[val],j)]+1 ans=max(ans,d2[(j,i)]) if(ans>=3): return ans return 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: n = len(A) if n < 3: return 0 # dp = [[2 for j in range(n)] for i in range(n)] # ans = 2 # hmap = {A[0]:0, A[1]:1} # for i in range(2, n): # for j in range(1, i): # pos = hmap.get(A[i]-A[j], -1) # if pos >= 0 and pos < j: # dp[i][j] = max(dp[i][j], dp[j][pos]+1) # ans = max(ans, dp[i][j]) # hmap[A[i]] = i # return ans if ans > 2 else 0 dp = [[2 for j in range(n)] for i in range(n)] ans = 2 for i in range(2, n): l, r = 0, i-1 while l < r: if A[l] + A[r] == A[i]: dp[i][r] = max(dp[i][r], dp[r][l] + 1) ans = max(ans, dp[i][r]) l += 1 r -= 1 elif A[l] + A[r] < A[i]: l += 1 else: r -= 1 return ans if ans > 2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: def _helper(l1, l2, cache): if A[l1] + A[l2] in table: l1, l2 = l2, table[A[l1] + A[l2]] return _helper(l1, l2, cache + 1) else: return cache if cache >= 3 else 0 ans = 0 table = {v:i for i, v in enumerate(A)} for i in range(len(A)): for j in range(i+1, len(A)): if A[i] + A[j] > A[-1]: break ans = max(ans, _helper(i, j, 2)) return ans
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: # dp = [[0 for i in range(len(A))] for j in range(len(len(A)))] ans = 0 d={} for i in range(len(A)): d[A[i]] = 1 for i in range(len(A)): for j in range(i+1,len(A)): a = A[i] b = A[j] l=2 while(d.get(a+b)!=None): l+=1 temp = b b = a+b a = temp ans = max(l,ans) if(ans>2): return ans return 0
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++.)
class Solution: def lenLongestFibSubseq(self, nums: List[int]) -> int: n=len(nums) dp=[[0 for x in range(n)] for y in range(n)] max_=0 for i in range(2,n): l=0 r=i-1 while l<=r: s=nums[l]+nums[r] if s>nums[i]: r-=1 elif s<nums[i]: l+=1 else: dp[r][i]=dp[l][r]+1 max_=max(max_,dp[r][i]) l+=1 r-=1 return max_ if max_==0 else max_+2
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: n = len(A) s = set() for i in A: s.add(i) res = 0 ll = 0 for i in range(n): for j in range(i+1,n): f1 = A[i] f2 = A[j] if f1+f2 in s: ll = 2 while f1+f2 in s: ll += 1 tmp = f2 f2 = f1+f2 f1 = tmp res = max(res,ll) return res
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: from collections import defaultdict used_tuples = set() max_len = 0 hist = set(A) for i in range(len(A) - 1): for j in range(i + 1, len(A)): curr_len = 0 s = A[i] l = A[j] if (s,l) in used_tuples: continue while s+l in hist: curr_len += 1 used_tuples.add((s,l)) old_s = s s = l l = s + old_s max_len = max(max_len, curr_len) return max_len + 2 if max_len > 0 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: n = len(A) dp = collections.defaultdict(int) ret = 0 a_set = set(A) for i in range(n): for j in range(i + 1, n): dp[(A[i], A[j])] = 2 left = A[j] - A[i] if left > A[i] or left not in a_set: continue dp[(A[i], A[j])] = max(dp[(A[i], A[j])], dp[(left, A[i])] + 1) ret = max(ret, dp[(A[i], A[j])]) return ret
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++.)
class Solution: def lenLongestFibSubseq(self, a: List[int]) -> int: s=set(a) c=0 for i in range(len(a)): for j in range(i+1,len(a)): x,y,l=a[i],a[j],2 while x+y in s: x,y=y,x+y l+=1 c=max(c,l) return c if c>2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: n = len(A) max_l = 0 cache = [[0 for j in range(n)] for i in range(n)] a_dict = {number: index for (index, number) in enumerate(A)} for i in range(n - 1, -1, -1): for j in range(n - 1, i, -1): if j == n - 1: cache[i][j] = 2 else: target = A[i] + A[j] if target in a_dict: cache[i][j] = cache[j][a_dict[target]] + 1 else: cache[i][j] = 2 if cache[i][j] > 2: max_l = max(cache[i][j], max_l) return max_l
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: pos = {A[i]: i for i in range(len(A))} dp = [[2 for j in range(len(A))] for i in range(len(A))] maxlen = 0 for z in range(2, len(A)): for x in range(z): y = pos.get(A[z] - A[x], -1) if A[x] < (A[z] - A[x]) and y != -1: dp[z][y] = dp[y][x] + 1 maxlen = max(maxlen, dp[z][y]) return maxlen if maxlen > 2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: N=len(A) index={n:i for i,n in enumerate(A)} dp=collections.defaultdict(lambda: 2) res=0 for i2 in range(N): for i1 in range(i2-1,-1,-1): n0=A[i2]-A[i1] if n0>=A[i1]: break if n0 in index: i0=index[n0] dp[(i1,i2)]=dp[(i0,i1)]+1 res=max(res,dp[(i1,i2)]) return res
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: n = len(A) dp = collections.defaultdict(int) ret = 0 a_set = set(A) for i in range(n): for j in range(i + 1, n): dp[(A[i], A[j])] = 2 left = A[j] - A[i] if left >= A[i] or left not in a_set: continue #print(left, A[i], A[j], dp[(left, A[i])]) dp[(A[i], A[j])] = dp[(left, A[i])] + 1 ret = max(ret, dp[(A[i], A[j])]) return ret
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++.)
class Solution: #from collections import deafal def lenLongestFibSubseq(self, A: List[int]) -> int: n = len(A) s = set(A) def helper(i,j): ans = 2 while(True): k = i+j if(k in s and k<=10**9): ans +=1 i = j j = k else: break return ans c = 0 for i in reversed(list(range(n-2))): for j in reversed(list(range(i+1,n-1))): c = max(c,helper(A[i],A[j])) return c if c>2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: longest = 0 coll = set(A) n = len(A) lookup = [[0 for _ in range(n)] for _ in range(n)] j = 1 for i in range(n - 2): if n - i + 2 < longest - lookup[i][j]: break for j in range(i + 1, n - 1): if n - j + 1 < longest - lookup[i][j]: break target = A[i] + A[j] prev = A[j] while target in coll: if lookup[i][j]: lookup[i][j] += 1 else: lookup[i][j] = 3 temp = target target += prev prev = temp longest = max(longest, lookup[i][j]) return longest
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: d = {} for i, v in enumerate(A): d[v] = i l = len(A) res = -1 for i in range(0, l): for j in range(i+1, l): one_behind = A[j] two_behind = A[i] total = one_behind + two_behind c = 0 while total in d: print((total, one_behind, two_behind)) if c == 0: c += 3 else: c += 1 tmp = one_behind one_behind = total two_behind = tmp total = one_behind + two_behind res = max(res, c) #break #print(res) return res
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++.)
class Solution: def lenLongestFibSubseq(self, nums: List[int]) -> int: n, ans = len(nums), 0 idx = {n: i for i, n in enumerate(nums)} dp = [[0]*n for _ in range(n)] for j in range(n): dp[0][j] = 2 dp[j][j] = 1 for i in range(1, n): for j in range(i+1, n): dp[i][j] = 2 if nums[i] > nums[j]//2 and nums[j]-nums[i] in idx: ii = idx[nums[j]-nums[i]] dp[i][j] = dp[ii][i] + 1 ans = max(ans, dp[i][j]) return ans if ans>2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: s = set(A) ans = 0 for i in range(len(A)): for j in range(i+1,len(A)): x,y = A[j],A[i]+A[j] l = 2 while y in s: x,y = y,x+y l += 1 ans = max(ans,l) return ans if ans >= 3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: d={} for i in range(len(A)): d[A[i]]=i dp=[[2 for i in range(len(A))] for j in range(len(A))] ans=0 for j in range(0,len(A)): for i in range(0,j): if A[j]-A[i] in d and d[A[j]-A[i]]<i: k= d[A[j]-A[i]] dp[i][j]=dp[k][i]+1 ans=max(dp[i][j],ans) return ans if ans>=3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, nums: List[int]) -> int: n = len(nums) idx = {n: i for i, n in enumerate(nums)} dp = [[0]*n for _ in range(n)] for j in range(n): dp[0][j] = 2 dp[j][j] = 1 ans = 0 for i in range(1, n): for j in range(i+1, n): if nums[i] <= nums[j]//2: dp[i][j] = 2 else: prev = nums[j]-nums[i] if prev in idx: dp[i][j] = dp[idx[prev]][i] + 1 else: dp[i][j] = 2 ans = max(ans, dp[i][j]) return ans if ans>2 else 0
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++.)
from collections import defaultdict class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: index_map = { x:i for i, x in enumerate(A) } longest = defaultdict(lambda: 2) ans = 0 for k in range(len(A)): for j in range(len(A)): target = A[k] - A[j] i = index_map.get(target, -1) if i >= 0 and i < j: cand = longest[j,k] = longest[i,j] + 1 ans = max(ans, cand) return ans
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++.)
class Solution(object): def lenLongestFibSubseq(self, A): S = set(A) ans = 0 for i in range(len(A)): for j in range(i+1, len(A)): x, y = A[j], A[i] + A[j] length = 2 while y in S: x, y = y, x + y length += 1 ans = max(ans, length) return ans if ans >= 3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: res = 2 S = set(A) for i in range (len(A)-2): if A[i] * (res - 1) * (res - 2) > A[-1]: break for j in range (i+1, len(A)-1): cnt = 2 a, b=A[j], A[i]+A[j] while b in S: cnt+=1 a, b = b, a+b res = max(cnt, res) if res > 2: return res else: return 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: maxlen = 0 dp = [[0 for _ in range(len(A))] for _ in range(len(A))] for i in range(2, len(A)): l, r = 0, i - 1 while l < r: s = A[l] + A[r] if s > A[i]: r -= 1 elif s < A[i]: l += 1 else: dp[r][i] = max(dp[r][i], dp[l][r] + 1) maxlen = max(maxlen, dp[r][i]) l += 1 r -= 1 return maxlen if maxlen == 0 else maxlen + 2
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: length = len(A) s = set(A) result = 0 for i in range(length-1): for j in range(i+1, length): a=A[i] b=A[j] count = 2 while a+b in s: a,b = b,a+b count+=1 result = max(result, count) return result if result > 2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: s = set(A) n = len(A) count = 0 for i in range(n): for j in range(i+1, n): x, y = A[j], A[i]+A[j] length = 2 while y in s: x, y = y, x+y length +=1 count = max(count, length) return count if count >= 3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: n = len(A) dp = [[2]*n for i in range(n)] map_ = collections.defaultdict(int) for i,j in enumerate(A): map_[j] = i # i:end j:start for i in range(2, n): for j in range(1, i): diff = A[i] - A[j] if diff in list(map_.keys()) and map_[diff] < j: k = map_[diff] dp[j][i] = max(dp[j][i], dp[k][j] + 1) max_ = max(dp[j][i] for i in range(n) for j in range(n)) if max_ == 2: return 0 else: return max_
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: start = 0 longest = 0 cur_total = 0 root = A[0] coll = set(A) n = len(A) cur = 2 target = [[None for _ in range(n)] for _ in range(n)] lookup = [[None for _ in range(n)] for _ in range(n)] for i in range(n - 2): for j in range(i + 1, n - 1): target[i][j] = A[i] + A[j] prev = A[j] while target[i][j] in coll: if lookup[i][j]: lookup[i][j] += 1 else: lookup[i][j] = 3 temp = target[i][j] target[i][j] += prev prev = temp longest = max(longest, lookup[i][j]) return longest
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: s=set(A) maxi=2 for i in range(len(A)-2): for j in range(i+1, len(A)-1): c=2 a=A[j] b=A[i]+A[j] while(b in s): c+=1 a,b= b, a+b maxi=max(maxi, c) return maxi if maxi>2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: mp = {} for v in A: mp[v] = set() result = 0 for i in range(len(A)): for j in range(i + 1, len(A)): a = A[i] b = A[j] l = 2 while True: if b in mp[a]: break if l != 2: mp[a].add(b) c = a + b if c not in mp: break a = b b = c l += 1 if l < 3: l = 0 result = max(result, l) return result
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: setA=set(A) #overlapping=set() r=0 for i in range(len(A)): start=A[i] for j in range(i+1,len(A)-1): prev_prev=start prev=A[j] count=0 while prev+prev_prev in setA: #overlapping.add(prev) #overlapping.add(prev_prev) prev_prev,prev=prev,prev+prev_prev count+=1 r=max(r,count) if r!=0: return r+2 else: return r
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: d = {} for i, v in enumerate(A): d[v] = i l = len(A) res = -1 for i in range(0, l): for j in range(i+1, l): one_behind = A[j] two_behind = A[i] total = one_behind + two_behind c = 0 while total in d: #print(total, one_behind, two_behind) if c == 0: c += 3 else: c += 1 one_behind, two_behind = total, one_behind total = one_behind + two_behind res = max(res, c) #break #print(res) return res
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: indices = {n: i for i, n in enumerate(A)} d = defaultdict(lambda: 2) ans = 0 for k, n in enumerate(A): for j in range(k-1, 0, -1): if (m := n - A[j]) not in indices: continue if (i := indices[m]) >= j: break d[j, k] = d[i, j] + 1 ans = max(ans, d[j, k]) return ans
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: s = set(A) ans = 0 for i in range(len(A)): for j in range(i+1,len(A)): x,y = A[i],A[j] l = 2 while x+y in s: x,y = y,x+y l += 1 ans = max(ans,l) return ans if ans >= 3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: d = {} for i, v in enumerate(A): d[v] = i l = len(A) res = -1 for i in range(0, l): for j in range(i+1, l): one_behind = A[j] two_behind = A[i] total = one_behind + two_behind c = 0 while total in d: #print(total, one_behind, two_behind) if c == 0: c += 3 else: c += 1 tmp = one_behind one_behind = total two_behind = tmp total = one_behind + two_behind res = max(res, c) #break #print(res) return res
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: N = len(A) st = set(A) res = 2 for i in range(N): for j in range(i+1, N): a, b, l = A[i], A[j], 2 while a + b in st: a, b, l = b, a+b, l+1 res = max(res, l) return res if res > 2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: n = len(A) two_sum = {} result = 0 for i in range(n - 1): for j in range(i + 1, n): curr_pair = (A[i], A[j]) prev_pair = (A[j] - A[i], A[i]) two_sum[curr_pair] = 2 if prev_pair in two_sum: two_sum[curr_pair] = max(two_sum[curr_pair], two_sum[prev_pair] + 1) result = max(result, two_sum[curr_pair]) return result
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++.)
from collections import Counter class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: res=0 d={x:i for i,x in enumerate(A)} n=len(A) dp=[[2 for j in range(n)] for i in range(n)] for i in range(2,n): for j in range(i): z=A[i] x=A[j] y=z-x k=d.get(y,-1) #x<y<z if x<y and k!=-1: dp[i][k]=1+dp[k][j] res=max(res,dp[i][k]) if res>2: return res return 0
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++.)
from bisect import bisect_left def BinarySearch(a, x): i = bisect_left(a, x) if i != len(a) and a[i] == x: return i else: return 0 class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: def get_length(x,y): s=0 while x+y in A: s+=1 x,y = y, x+y return s if len(A) < 3: return 0 ans = 0 sum_lim = A[-1] for fi in range(len(A)-2): curr_ans = 0 temp_fi = fi si = temp_fi+1 # print(\"======={}====================\".format(fi)) while si< len(A): reqd_sum = A[temp_fi]+A[si] if reqd_sum > sum_lim: break pres = BinarySearch(A, reqd_sum) if pres: # temp_fi = si # si = pres curr_ans = 1+ get_length(A[si], A[pres]) ans = max(ans, curr_ans) si += 1 return ans+2 if ans > 0 else ans
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: s, memo = set(A), {} for i in range(len(A)): for j in range(i): if (A[i] - A[j]) in s and (A[i] - A[j]) < A[j]: memo[A[j], A[i]] = memo.get( (A[i] - A[j], A[j]), 2) + 1 return max(memo.values() or [0])
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: # only need the first 2 elements to define a fib seq setA = set(A) rint = 0 def getLen(i, j): a, b = A[i], A[j] if a + b not in setA: return 0 length = 2 while a + b in setA: length += 1 a, b = b, a + b return length for i in range(len(A) - 2): for j in range(i + 1, len(A) - 1): if A[j] - A[i] in setA and A[j] - A[i] < A[i]: continue rint = max(rint, getLen(i, j)) # print(i, j, getLen(i, j)) return rint
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: longest = 0 coll = set(A) n = len(A) lookup = [[0 for _ in range(n)] for _ in range(n)] for i in range(n - 2): for j in range(i + 1, n - 1): if n - j + 1 < longest - lookup[i][j]: break target = A[i] + A[j] prev = A[j] while target in coll: if lookup[i][j]: lookup[i][j] += 1 else: lookup[i][j] = 3 temp = target target += prev prev = temp longest = max(longest, lookup[i][j]) return longest
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++.)
class Solution: def lenLongestFibSubseq(self, nums: List[int]) -> int: n=len(nums) dp=[[0 for x in range(n)] for y in range(n)] max_=0 for i in range(2,n): l=0 r=i-1 min_possible=nums[0]+nums[1] max_possible=nums[r]+nums[r-1] if nums[i]<min_possible or nums[i]>max_possible: continue while l<=r: s=nums[l]+nums[r] if s>nums[i]: r-=1 elif s<nums[i]: l+=1 else: dp[r][i]=dp[l][r]+1 max_=max(max_,dp[r][i]) l+=1 r-=1 return max_ if max_==0 else max_+2
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: if len(A) <= 2: return 0 dp = {(A[1], A[0]): 2} maxx = 0 for i in range(2, len(A)): j = i-1 while j >= 0: v = A[i] - A[j] if v < A[j] and (A[j], v) in dp: maxx = max(maxx, dp[(A[j], v)]+1) dp[(A[i], A[j])] = dp[(A[j], v)]+1 else: dp[(A[i], A[j])] = 2 j -= 1 #print(dp) return maxx
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++.)
from collections import defaultdict class Solution: def lenLongestFibSubseq(self, ordered_nums: List[int]) -> int: def dfs(prev, curr): if (prev, curr) in explored: return -1 elif prev + curr not in unordered_nums: return 2 else: explored.add((prev, curr)) return 1 + dfs(curr, prev + curr) unordered_nums = {n for n in ordered_nums} explored = set() path_len = 0 for i in range(len(unordered_nums)): for j in range(i + 1, len(unordered_nums)): path_len = max(path_len, dfs(ordered_nums[i], ordered_nums[j])) return path_len if path_len >= 3 else 0
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++.)
from collections import defaultdict class Solution: def lenLongestFibSubseq(self, nums: List[int]) -> int: num_to_idx = {n: i for i, n in enumerate(nums)} mat = [[0 for _ in range(len(nums))] for _ in range(len(nums))] path_len = 0 for i in range(len(mat)): for j in range(i + 1, len(mat)): n = nums[j] - nums[i] if n < nums[i] and n in num_to_idx: mat[i][j] = mat[num_to_idx[n]][i] + 1 else: mat[i][j] = 2 path_len = max(path_len, mat[i][j]) return path_len if path_len >= 3 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: S = set(A) res = 0 for i in range(len(A)): for j in range(i+1,len(A)): f1 ,f2= A[i],A[j] length = 0 if(f1+f2 in S): length = 2 while(f1+f2 in S): length+=1 tmp = f1+f2 f1 = f2 f2 = tmp res = max(length,res) return res
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: S = set(A) ans = 2 for i in range(len(A)): for j in range(i + 1, len(A)): a = A[i] b = A[j] l = 2 while((a+b) in S): temp = a a = b b = temp + b l += 1 ans = max(ans, l) if ans < 3: return 0 return ans
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: S = set(A) res = 2 for i in range(len(A) - 2): if A[i] * (res - 1) * (res - 2) > A[-1]: break for j in range(i + 1, len(A) - 1): cnt = 2 a, b = A[j], A[i] + A[j] while b in S: cnt += 1 a, b = b, a + b res = max(res, cnt) return res if res > 2 else 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: A.sort() S = (set(A)) maxlen = 0 for i in range(len(A)): for j in range(i+1,len(A)): a,b = A[j],A[i]+A[j] count = 2 while b in S: count+=1 a,b = b,a+b maxlen = max(maxlen,count) if maxlen >= 3: return maxlen return 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: dp = dict() for i in A: dp[(i,i)] = 0 n = len(A) for i in range(n): for j in range(i+1,n): if A[j]-A[i]<A[i] and A[j]-A[i]>=0 and (A[j]-A[i],A[i]) in dp: val = dp[(A[j]-A[i],A[i])] + 1 else: val = 2 dp[(A[i],A[j])] = val a = max(list(dp.values())) if a>2: return a return 0
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++.)
class Solution: def lenLongestFibSubseq(self, A: List[int]) -> int: longest = 0 coll = set(A) n = len(A) target = [[None for _ in range(n)] for _ in range(n)] lookup = [[None for _ in range(n)] for _ in range(n)] for i in range(n - 2): for j in range(i + 1, n - 1): target[i][j] = A[i] + A[j] prev = A[j] while target[i][j] in coll: if lookup[i][j]: lookup[i][j] += 1 else: lookup[i][j] = 3 temp = target[i][j] target[i][j] += prev prev = temp longest = max(longest, lookup[i][j]) return longest