Troubleshooting Longest Increasing Subsequence

I'm having a bit of difficulty trying to implement the longest increasing subsequence algorithm. I found a <<crapware site>> online that looks helpful, but I'm having trouble translating the pseudocode into code.


I'm using Python, and I've written the following function:

Code:

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def longest_increasing_subsequence(arr):
    n = len(arr)
    lis = [1]*n
   
    for i in range(1, n):
        for j in range(0, i):
            if arr[i] > arr[j] and lis[i] < lis[j] + 1 :
                lis[i] = lis[j]+1
 
    maximum = 0
 
    for i in range(n):
        maximum = max(maximum, lis[i])
 
    return maximum

---

When I try to run the code, I get the following error:

Code:

---

NameError: name 'arr' is not defined

---

I'm not sure what I'm doing wrong. Any help would be appreciated!
Thank you.

It looks like the error lies in code that you did not show, e.g., you may have made a mistake when calling the function.