2831. Find the Longest Equal Subarray

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Think as dp as first, but the dataset is 10^5 , it should only be linear or n log n.

When n log n solution, maybe binary search or sort. but not see any efficency here.

class Solution:
    def longestEqualSubarray(self, nums: List[int], k: int) -> int:
        
        n = len(nums)
        M = defaultdict(list)
        
        for i in range(n):
            M[nums[i]].append(i)
        
        res = 1
        
        for ll in M.values():
            current = 1
            ck = k
            l = 0
            for i in range(1, len(ll)):
                ck -= ll[i] - ll[i-1] - 1
                while ck < 0 and l < i:
                    ck += ll[l+1] - ll[l] - 1
                    l += 1

                current = i - l + 1
            
                res = max(res, current)
            
        return res