<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 {
public:

    void buildnext(vector<int>& nums, vector<int>& next)
    {
        int i = 0, j = 0;
        while(i < nums.size())
        {
            if (i != j && nums[i] == nums[j])
            {
                next[i] = j + 1;
                ++i;
                ++j;
            }
            else if (j > 0)
            {
                j = next[j-1];
            }
            else
            {
                ++i;
                j = 0;
            }
        }
    }

    int findLength(vector<int>& nums1, vector<int>& nums2) {
        int ans = 0;

        if (nums1.size() > nums2.size())
            swap(nums1, nums2);

        while(nums1.size())
        {
            vector<int> next(nums1.size(), 0);
            buildnext(nums1, next);

            //for (auto& n: next)
                //cout<<n<<" ";
                //cout<<endl;

            int j = 0, i = 0;
            while(i < nums2.size())
            {
                if (nums1[j] == nums2[i])
                {
                    ++i;
                    ++j;
                    //cout<<"i:"<<i<<" j:"<<j<<endl;
                    ans = max(j, ans);
                }
                else if (j != 0)
                {
                    j = next[j-1];
                }
                else
                    ++i;
                
                if (j == nums1.size())
                    j = next[j-1];
            }
            
            nums1.erase(nums1.begin());
        }

        return ans;
    }
};
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