class Solution {
 public:
  int findLength(vector<int>& nums1, vector<int>& nums2) {
    const int m = nums1.size();
    const int n = nums2.size();
    int ans = 0;
    // dp[i][j] := max length of nums1[i:] and nums2[j:]
    vector<vector<int>> dp(m + 1, vector<int>(n + 1));

    for (int i = m - 1; i >= 0; --i)
      for (int j = n - 1; j >= 0; --j)
        if (nums1[i] == nums2[j]) {
          dp[i][j] = dp[i + 1][j + 1] + 1;
          ans = max(ans, dp[i][j]);
        }

    return ans;
  }
};