let's try this again shall we

problems 1->10 of LC150

169-majority-element/soln.py

@@ -0,0 +1,26 @@
+def majorityElement(self, nums: list[int]) -> int:
+    # O(n) time, O(n) space
+    # cnts = {}
+    # for x in nums:
+    #     cnts[x] = cnts.get(x, 0) + 1
+    #     if cnts[x] > len(nums) / 2:
+    #         return x
+
+    # O(n) time, O(1) space
+    # Boyer-Moore majority vote algorithm
+    # given: majority exists (>n/2, NOT just n/2)
+    # voters fight 1v1 MAD, last standing must be of majority
+    leading_candidate = nums[0]
+    count = 0
+    for x in nums:
+        # MAD; new leader must emerge
+        if count == 0:
+            count = 1
+            leading_candidate = x
+        # dissent; majority weakens
+        elif x != leading_candidate:
+            count -= 1
+        # assent; majority strengthens
+        else:
+            count += 1
+    return leading_candidate