Program to find duplicate elements and delete last occurrence of them in Python

Suppose we have a list of numbers A, we have to find all duplicate numbers and remove their last occurrences.

So, if the input is like [10, 30, 40, 10, 30, 50], then the output will be [10, 30, 40, 50]

To solve this, we will follow these steps −

• seen:= a new map
• d:= a new map
• for i in range 0 to size of nums, do
  • if nums[i] is not in d, then
    • d[nums[i]]:= 1
  • otherwise,
    • d[nums[i]] := d[nums[i]] + 1
• i:= 0
• while i < size of nums, do
  • n:= d[nums[i]]
  • if nums[i] is not in seen, then
    • seen[nums[i]]:= 1
  • otherwise,
    • seen[nums[i]] := seen[nums[i]] + 1
  • if n is same as seen[nums[i]] and n > 1, then
    • delete ith element from nums
    • i := i - 1
  • i := i + 1
• return nums

Let us see the following implementation to get better understanding −

Example

 Live Demo

class Solution:    def solve(self, nums):       seen={}       d={}       for i in range(len(nums)):          if not nums[i] in d:             d[nums[i]]=1          else:             d[nums[i]]+=1       i=0       while i < len(nums):          n=d[nums[i]]          if not nums[i] in seen:             seen[nums[i]]=1          else:             seen[nums[i]]+=1          if n == seen[nums[i]] and n > 1:             nums.pop(i)          i-=1          i+=1       return nums ob = Solution() print(ob.solve([10, 30, 40, 10, 30, 50]))

Input

[10, 30, 40, 10, 30, 50]

Output

[10, 30, 40, 50]