let's try this again shall we

problems 1->10 of LC150

26-remove-duplicates-from-sorted-array/soln.py

@@ -0,0 +1,19 @@
+class Solution:
+    def removeDuplicates(self, nums: list[int]) -> int:
+        # naive, hashmap
+        # cnts = {}
+        # k = 0
+        # for x in nums:
+        #     if cnts.get(x) == None:
+        #         k += 1
+        #     cnts[x] = cnts.get(x, 0) + 1
+        # for idx, key in enumerate(cnts.keys()):
+        #     nums[idx] = key
+        # return k
+        # two pointer
+        last_unique = 0
+        for fast in range(1, len(nums)):
+            if nums[last_unique] != nums[fast]:
+                last_unique += 1
+                nums[last_unique] = nums[fast]
+        return last_unique + 1  # zero-indexed