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:
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.
Examples
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
2719. Count of Integers
Hard
50 Points
Math
String
Dynamic Programming
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:
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.
Examples
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.