2141. Maximum Running Time of N Computers

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class Solution:
    def maxRunTime(self, n: int, batteries: List[int]) -> int:

        l, r = 0, sum(batteries) // n
        
        # greedy
        def check(x):
            return sum(min(x, b) for b in batteries) >= n * x  # required capacity
        
        while l < r:
            mid = r  - (r - l)//2
            if check(mid):
                l = mid
            else:
                r = mid-1
        return r