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Unit 2 Session 2 (Click for link to problem statements)

U-nderstand

Understand what the interviewer is asking for by using test cases and questions about the problem.

P-lan

Plan the solution with appropriate visualizations and pseudocode.

General Idea: Loop backwards through the list, and each time we find a new element, add it to the front of a new list.

1) Create an empty list to store unique numbers 2) Starting at the END of the nums list: a) If the number is not already in unique, insert it at the beginning of unique 3) Return the unique nums

I-mplement

def remove_duplicates_from_front(nums): unique_nums = [] for i in range(len(nums)-1, -1, -1): if nums[i] not in unique_nums: unique_nums.insert(0, nums[i]) return unique_nums

Alternate solution using a modified frequency map:

def remove_duplicates_from_front(nums): frequency_map = {} for num in nums: frequency_map[num] = True last_occurrences = [] for num in nums[::-1]: # Reverse iterate if frequency_map[num]: last_occurrences.append(num) frequency_map[num] = False return last_occurrences[::-1] # Reverse again to original order