spoj#PR003004. Digit Sum
Digit Sum
For a pair of integers a and b, the digit sum of the interval [a,b] is defined as the sum of all digits occurring in all numbers between (and including) a and b. For example, the digit sum of [28, 31] can be calculated as:
2+8 + 2+9 + 3+0 + 3+1 = 28
Given the numbers a and b, calculate the digit sum of [a,b].
For a pair of integers a and b, the digit sum of the interval [a,b] is defined as the sum of all digits occurring in all numbers between (and including) a and b. For example, the digit sum of [28, 31] can be calculated as:
2+8 + 2+9 + 3+0 + 3+1 = 28
Given the numbers a and b, calculate the digit sum of [a,b].
Input
On the first line one positive number: the number of test cases, at most 100.
After that per test case:
- one line with two space-separated integers, a and b (0 <= a <= b <= 10^15).
Output
Per test case:
- one line with an integer: the digit sum of [a,b];
Example
Input: 3 0 10 28 31 1234 56789</p>Output: 46 28 1128600