leetcode 1742. Maximum Number of Balls in a Box(python)

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描述

You are working in a ball factory where you have n balls numbered from lowLimit up to highLimit inclusive (i.e., n == highLimit - lowLimit + 1), and an infinite number of boxes numbered from 1 to infinity.

Your job at this factory is to put each ball in the box with a number equal to the sum of digits of the ball's number. For example, the ball number 321 will be put in the box number 3 + 2 + 1 = 6 and the ball number 10 will be put in the box number 1 + 0 = 1.

Given two integers lowLimit and highLimit, return the number of balls in the box with the most balls.

Example 1:

Input: lowLimit = 1, highLimit = 10
Output: 2
Explanation:
Box Number:  1 2 3 4 5 6 7 8 9 10 11 ...
Ball Count:  2 1 1 1 1 1 1 1 1 0  0  ...
Box 1 has the most number of balls with 2 balls.	

Example 2:

Input: lowLimit = 5, highLimit = 15
Output: 2
Explanation:
Box Number:  1 2 3 4 5 6 7 8 9 10 11 ...
Ball Count:  1 1 1 1 2 2 1 1 1 0  0  ...
Boxes 5 and 6 have the most number of balls with 2 balls in each.

Example 3:

Input: lowLimit = 19, highLimit = 28
Output: 2
Explanation:
Box Number:  1 2 3 4 5 6 7 8 9 10 11 12 ...
Ball Count:  0 1 1 1 1 1 1 1 1 2  0  0  ...
Box 10 has the most number of balls with 2 balls.

Note:

1 <= lowLimit <= highLimit <= 10^5

解析

根据题意,只需要遍历从 lowLimit 到 highLimit 的数值 item ,然后使用字典 balls 保存其放的球数,以 item 每个位数上的和为 key ,以可以存放的球数为 value ,遍历结束即可得到每个 key 的结果,然后找出最大值即可。

解答

class Solution(object):
    def countBalls(self, lowLimit, highLimit):
        """
        :type lowLimit: int
        :type highLimit: int
        :rtype: int
        """
        balls = {}
        def sum(num):
            result = 0
            while num>0:
                result += num%10
                num=num//10
            return result
        for item in range(lowLimit,highLimit+1):
            tmp = sum(item)
            if tmp not in balls:
                balls[tmp]=1
            else:
                balls[tmp]+=1
        return max(balls.values())
        	      
		

运行结果

Runtime: 504 ms, faster than 79.76% of Python online submissions for Maximum Number of Balls in a Box.
Memory Usage: 15.9 MB, less than 86.84% of Python online submissions for Maximum Number of Balls in a Box.

原题链接:leetcode.com/problems/ma…

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