Create longest-happy-string.py

Author: kamyu104

Python/longest-happy-string.py

@@ -0,0 +1,63 @@
+# Time:  O(n)
+# Space: O(1)
+
+import heapq
+
+
+class Solution(object):
+    def longestDiverseString(self, a, b, c):
+        """
+        :type a: int
+        :type b: int
+        :type c: int
+        :rtype: str
+        """
+        max_heap = []
+        if a:
+            heapq.heappush(max_heap, (-a, 'a'))
+        if b:
+            heapq.heappush(max_heap, (-b, 'b'))
+        if c:
+            heapq.heappush(max_heap, (-c, 'c'))
+        result = []
+        while max_heap:
+            count1, c1 = heappop(max_heap)
+            if len(result) >= 2 and result[-1] == result[-2] == c1:
+                if not max_heap:
+                    return "".join(result)
+                count2, c2 = heappop(max_heap)
+                result.append(c2)
+                count2 += 1
+                if count2:
+                    heapq.heappush(max_heap, (count2, c2))
+                heapq.heappush(max_heap, (count1, c1))
+                continue
+            result.append(c1)
+            count1 += 1
+            if count1 != 0:
+                heappush(max_heap, (count1, c1))
+        return "".join(result)
+
+
+# Time:  O(n)
+# Space: O(1)
+class Solution2(object):
+    def longestDiverseString(self, a, b, c):
+        """
+        :type a: int
+        :type b: int
+        :type c: int
+        :rtype: str
+        """
+        choices = [[a, 'a'], [b, 'b'], [c, 'c']]
+        result = []
+        for _ in xrange(a+b+c):
+            choices.sort(reverse=True)
+            for i, (x, c) in enumerate(choices):
+                if x and result[-2:] != [c, c]:
+                    result.append(c)
+                    choices[i][0] -= 1
+                    break
+            else:
+                break
+        return "".join(result)