<p>Given two integer arrays <code>nums1</code> and <code>nums2</code>, return <em>the maximum length of a subarray that appears in <strong>both</strong> arrays</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums1 = [1,2,3,2,1], nums2 = [3,2,1,4,7]
<strong>Output:</strong> 3
<strong>Explanation:</strong> The repeated subarray with maximum length is [3,2,1].
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums1 = [0,0,0,0,0], nums2 = [0,0,0,0,0]
<strong>Output:</strong> 5
<strong>Explanation:</strong> The repeated subarray with maximum length is [0,0,0,0,0].
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums1.length, nums2.length &lt;= 1000</code></li>
	<li><code>0 &lt;= nums1[i], nums2[i] &lt;= 100</code></li>
</ul>

class Solution:
    # O(n*m) time, O(n) space
    # def findLength(self, nums1: List[int], nums2: List[int]) -> int:
    #     n = len(nums1)
    #     m = len(nums2)
    #     dp = [0] * n
    #     max_len = 0
    #     for i in range(m):
    #         for j in reversed(range(n)):
    #             if nums1[j] == nums2[i]:
    #                 dp[j] = (dp[j - 1] if j > 0 else 0) + 1
    #                 max_len = max(max_len, dp[j])
    #             else:
    #                 dp[j] = 0
    #     return max_len

    # O(nlogn) time, O(1) space, TLE
    def findLength(self, nums1: List[int], nums2: List[int]) -> int:
        n = len(nums1)
        m = len(nums2)
        l, r = 0, min(n, m)
        while l <= r:
            mid = l + (r - l) // 2
            if hasCommonArray(nums1, nums2, mid):
                l = mid + 1
            else:
                r = mid - 1
        return r

def hasCommonArray(nums1, nums2, length):
    seen = set(tuple(nums1[i:i+length]) for i in range(len(nums1) - length + 1))
    return any(tuple(nums2[j:j+length]) in seen for j in range(len(nums2) - length + 1))

#     # O(n^3logn) time, O(1) space, TLE
#     def findLength(self, nums1: List[int], nums2: List[int]) -> int:
#         n = len(nums1)
#         m = len(nums2)
#         l, r = 0, min(n, m)
#         while l <= r:
#             mid = l + (r - l) // 2
#             if hasCommonArray(nums1, nums2, mid):
#                 l = mid + 1
#             else:
#                 r = mid - 1
#         return r

# def hasCommonArray(nums1, nums2, sz):
#     n = len(nums1)
#     m = len(nums2)
#     for i in range(n - sz + 1):
#         for j in range(m - sz + 1):
#             found = True
#             for k in range(sz):
#                 if nums1[i + k] != nums2[j + k]:
#                     found = False
#                     break
#             if found:
#                 return True
#     return False

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