Example 1:
Input: lowLimit = 1, highLimit = 10
Output: 2
Explanation:
Example 2:
Input: lowLimit = 5, highLimit = 15
Output: 2
Explanation:
Example 3:
Input: lowLimit = 19, highLimit = 28
Output: 2
Explanation:
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 the digits of the ball's number. For example, the ball numbered 321 will be put in the box number 3 + 2 + 1 = 6 and the ball numbered 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.
Box 1 receives both ball 1 (1) and ball 10 (1+0), so the most-filled box has 2 balls.
Box 6 has balls 6 and 15; no other box has more than 1.
Balls 19 (1+9=10) and 28 (2+8=10) both land in box 10; every other box has 1 ball.
1 <= lowLimit <= highLimit <= 10^5