Update maximum-running-time-of-n-computers.py

Author: kamyu104

Python/maximum-running-time-of-n-computers.py

@@ -20,3 +20,26 @@ def maxRunTime(self, n, batteries):
             n -= 1
             total -= -heapq.heappop(batteries)
         return total//n
+
+
+# Time:  O(nlogr), r is the range of possible minutes
+# Space: O(1)
+# binary search
+class Solution2(object):
+    def maxRunTime(self, n, batteries):
+        """
+        :type n: int
+        :type batteries: List[int]
+        :rtype: int
+        """
+        def check(n, batteries, x):
+            return sum(min(b, x) for b in batteries) >= n*x
+
+        left, right = min(batteries), sum(batteries)//n
+        while left <= right:
+            mid = left + (right-left)//2
+            if not check(n, batteries, mid):
+                right = mid-1
+            else:
+                left = mid+1
+        return right