Complexity Analysis
def remove_all(arr, val):
while val in arr:
arr.remove(val)
return arrWhat is the time and space complexity?
Work it out before scrolling down.
Time
O(n²)
Space
O(1)
How to derive it
Trap: both `val in arr` and `arr.remove(val)` are O(n) each. If val appears k times, the while loop runs k times, each iteration doing O(n) work → O(k × n). Worst case k = n (all elements equal val), giving O(n²). A single-pass filter `[x for x in arr if x != val]` would be O(n).