Create minimum-operations-to-make-the-array-alternating.py

Author: kamyu104

Python/minimum-operations-to-make-the-array-alternating.py

@@ -0,0 +1,30 @@
+# Time:  O(n)
+# Space: O(n)
+
+import collections
+
+
+# freq table
+class Solution(object):
+    def minimumOperations(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: int
+        """
+        def find_top1_and_top2(cnt):
+            top1 = top2 = -1
+            for k, v in cnt.iteritems():
+                if top1 == -1 or v >= cnt[top1]:
+                    top1, top2 = k, top1
+                elif top2 == -1 or v > cnt[top2]:
+                    top2 = k
+            return top1, top2
+
+        even = collections.Counter(nums[i] for i in xrange(0, len(nums), 2))
+        odd = collections.Counter(nums[i] for i in xrange(1, len(nums), 2))
+        even_top = find_top1_and_top2(even)
+        odd_top = find_top1_and_top2(odd)
+        if even_top[0] != odd_top[0]:
+            return len(nums)-even[even_top[0]]-(odd[odd_top[0]] if odd_top[0] != -1 else 0)
+        return min(len(nums)-even[even_top[0]]-(odd[odd_top[1]] if odd_top[1] != -1 else 0),
+                   len(nums)-odd[odd_top[0]]-(even[even_top[1]] if even_top[1] != -1 else 0))