codeforces#P1538F. Interesting Function
Interesting Function
Description
You are given two integers $l$ and $r$, where $l < r$. We will add $1$ to $l$ until the result is equal to $r$. Thus, there will be exactly $r-l$ additions performed. For each such addition, let's look at the number of digits that will be changed after it.
For example:
- if $l=909$, then adding one will result in $910$ and $2$ digits will be changed;
- if you add one to $l=9$, the result will be $10$ and $2$ digits will also be changed;
- if you add one to $l=489999$, the result will be $490000$ and $5$ digits will be changed.
Changed digits always form a suffix of the result written in the decimal system.
Output the total number of changed digits, if you want to get $r$ from $l$, adding $1$ each time.
The first line contains an integer $t$ ($1 \le t \le 10^4$). Then $t$ test cases follow.
Each test case is characterized by two integers $l$ and $r$ ($1 \le l < r \le 10^9$).
For each test case, calculate the total number of changed digits if you want to get $r$ from $l$, adding one each time.
Input
The first line contains an integer $t$ ($1 \le t \le 10^4$). Then $t$ test cases follow.
Each test case is characterized by two integers $l$ and $r$ ($1 \le l < r \le 10^9$).
Output
For each test case, calculate the total number of changed digits if you want to get $r$ from $l$, adding one each time.
Samples
4
1 9
9 10
10 20
1 1000000000
8
2
11
1111111110