## PR003004 - Digit Sum

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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

Output:
46
28
1128600```

 < Previous 1 2 Next > rangey_18o3_20: 2021-08-27 17:58:40 Unsigned Long Long for the wins Thanks to everyone who commented about this and helped me save time av1shek: 2021-07-06 11:36:58 getting wrong answer on using long long in c++ Last edit: 2021-07-06 16:37:45 av1shek: 2021-07-06 11:35:03 @dwij28 instead of long long, use unsigned long long int codeman98: 2021-04-29 19:44:29 Getting wrong answer. [NG]: For the sample cases you provided, you're getting correct results. Don't post any code in the comments, use forum for code review and debug. Last edit: 2021-04-30 11:51:34 abhishen99: 2020-12-24 13:15:36 easy peasy ... vyavaharesid: 2020-05-20 16:13:01 can anyone help me iam getting tle tried code of gfg digit sum plz give any link for studying rul0: 2020-02-09 20:05:37 this problem have something rare. I have the same situation as dwij28, 3 comments below ca999: 2019-12-05 11:20:16 Hmm weird, I got WA for CRCRC1C, but got AC for this one with literally the same code. Akshay Aradhya: 2018-02-04 13:04:47 LOL I forgot to change my DP memory from CPCRC1C. Changed it and AC :) dwij28: 2016-06-29 11:58:48 Answer should technically always fit in the range of long long int. But my C++ solution gives a WA but its exact 100% translation into python gives AC. Can someone tell me what could be the reason behind it ?