codeforces#P1036C. Classy Numbers
Classy Numbers
Description
Let's call some positive integer classy if its decimal representation contains no more than $3$ non-zero digits. For example, numbers $4$, $200000$, $10203$ are classy and numbers $4231$, $102306$, $7277420000$ are not.
You are given a segment $[L; R]$. Count the number of classy integers $x$ such that $L \le x \le R$.
Each testcase contains several segments, for each of them you are required to solve the problem separately.
The first line contains a single integer $T$ ($1 \le T \le 10^4$) — the number of segments in a testcase.
Each of the next $T$ lines contains two integers $L_i$ and $R_i$ ($1 \le L_i \le R_i \le 10^{18}$).
Print $T$ lines — the $i$-th line should contain the number of classy integers on a segment $[L_i; R_i]$.
Input
The first line contains a single integer $T$ ($1 \le T \le 10^4$) — the number of segments in a testcase.
Each of the next $T$ lines contains two integers $L_i$ and $R_i$ ($1 \le L_i \le R_i \le 10^{18}$).
Output
Print $T$ lines — the $i$-th line should contain the number of classy integers on a segment $[L_i; R_i]$.
Samples
4
1 1000
1024 1024
65536 65536
999999 1000001
1000
1
0
2