最长上升子序列问题

int lengthOfLIS(vector<int>& nums)
{
    int n = nums.size();
    if (n == 0)  return 0;
    vector<int> dp(n, 0);
    int res = 1;
    for (int i = 0; i < n; i++)
    {
        dp[i] = 1;
        for (int j = 0; j < i; j++)
        {
            if (nums[j] < nums[i])
            {
                dp[i] = max(dp[i], dp[j] + 1);
            }
        }
        res = max(res, dp[i]);
    }
    return res;
}