Class Solution


  • public class Solution
    extends Object
    2719 - Count of Integers.

    Hard

    You are given two numeric strings num1 and num2 and two integers max_sum and min_sum. We denote an integer x to be good if:

    • num1 <= x <= num2
    • min_sum <= digit_sum(x) <= max_sum.

    Return the number of good integers. Since the answer may be large, return it modulo 109 + 7.

    Note that digit_sum(x) denotes the sum of the digits of x.

    Example 1:

    Input: num1 = “1”, num2 = “12”, min_sum = 1, max_sum = 8

    Output: 11

    Explanation: There are 11 integers whose sum of digits lies between 1 and 8 are 1,2,3,4,5,6,7,8,10,11, and 12. Thus, we return 11.

    Example 2:

    Input: num1 = “1”, num2 = “5”, min_sum = 1, max_sum = 5

    Output: 5

    Explanation: The 5 integers whose sum of digits lies between 1 and 5 are 1,2,3,4, and 5. Thus, we return 5.

    Constraints:

    • 1 <= num1 <= num2 <= 1022
    • 1 <= min_sum <= max_sum <= 400
    • Constructor Detail

      • Solution

        public Solution()
    • Method Detail

      • count

        public int count​(String num1,
                         String num2,
                         int minSum,
                         int maxSum)