Description
You are given an integer array nums and a positive integer k.
A subsequence sub of nums with length x is called valid if it satisfies:
(sub[0] + sub[1]) % k == (sub[1] + sub[2]) % k == ... == (sub[x - 2] + sub[x - 1]) % k.
nums.
Example 1:
Input: nums = [1,2,3,4,5], k = 2
Output: 5
Explanation:
The longest valid subsequence is [1, 2, 3, 4, 5].
Example 2:
Input: nums = [1,4,2,3,1,4], k = 3
Output: 4
Explanation:
The longest valid subsequence is [1, 4, 1, 4].
Constraints:
2 <= nums.length <= 1031 <= nums[i] <= 1071 <= k <= 103
Solution
Python3
class Solution:
def maximumLength(self, nums: List[int], k: int) -> int:
N = len(nums)
res = 0
for mod in range(k):
dp = [0] * k
for x in nums:
x %= k
dp[x] = max(dp[x % k], dp[(mod - x + k) % k] + 1)
res = max(res, max(dp))
return res