<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:
    def findLength(self, nums1: List[int], nums2: List[int]) -> int:
        # # nums1, nums2 = "".join(map(chr, nums1)), "".join(map(chr, nums2))
        # nums1 = ''.join([str(i) for i in nums1])
        # nums2 = ''.join([str(i) for i in nums2])
        # M = len(nums1)
        # N = len(nums2)
        # def has_subarray(m):
        #     # seen = {nums1[i:i + n] for i in range(len(nums1) - n + 1)}
        #     seen = {nums1[i:i + m] for i in range(len(nums1) - m + 1)}
        #     for i in range(len(nums2) - m + 1):
        #         if nums2[i:i + m] in seen:
        #             return True
        #     # return any(nums2[i:i + n] in seen for i in range(len(nums2) - n + 1))
        #     return False

        # lo, hi = 0, min(len(nums1), len(nums2))
        # while lo < hi:
        #     mid = (lo + hi + 1) // 2
        #     if has_subarray(mid):
        #         lo = mid
        #     else:
        #         hi = mid - 1
        # return lo
        
        M = len(nums1)
        N = len(nums2)
        l = 0
        r = min(M, N)
        while l < r:
            m = (l + r + 1) // 2
            seen = {tuple(nums1[i:i + m]) for i in range(M - m + 1)}
            for i in range(N - m + 1):
                if tuple(nums2[i:i + m]) in seen:
                    l = m
                    break
            else:
                r = m - 1
        return l

#         # M = len(nums1)
#         # N = len(nums2)
#         # l = [[0] * (N + 1) for _ in range(M + 1)]
#         # c = 0
#         # for i in range(M - 1, -1, -1):
#         #     for j in range(N - 1, -1, -1):
#         #         if nums1[i] == nums2[j]:
#         #             l[i][j] = l[i + 1][j + 1] + 1
#         #             c = max(c, l[i][j])
#         # return c

#         #   1 2 3 2 1
#         # 3 0 0 3 0 0 
#         # 2 0 1 0 2 0 
#         # 1 1 0 0 0 1
#         # 4 0 0 0 0 0
#         # 7 0 0 0 0 0
        
21300