Polo the Penguin and the Numbers
All submissions for this problem are available.
Read problems statements in Russian here
Polo, the Penguin, likes numbers. He says that the goodness of a number is itself multiplied by the number of digits in it's decimal representation. For example, the goodness of the integer 474 is 474*3 = 1422.
Help him to count the sum of goodness of all integers from L to R, inclusive. Since the answer can be too large, output it modulo 1,000,000,007 (10^9+7).
The first line of the input contains an integer T denoting the number of test cases. The description of T test cases follows. The only line of each test case contains the pair of integers L and R, separated by a single space.
For each test case, output a single line containing the answer to the corresponding test case.
- 1 ≤ T ≤ 1,000
- 1 ≤ L ≤ R ≤ 1,000,000,000 (10^9)
Input: 1 9 12 Output: 75
Example case 1. The answer is 9*1 + 10*2 + 11*2 + 12*2 = 75.
|Tags||ad-hoc, cook39, easy, witua|
|Time Limit:||1 sec|
|Source Limit:||50000 Bytes|
|Languages:||C, CPP14, JAVA, PYTH, PYTH 3.5, CS2, PAS fpc, PAS gpc, RUBY, PHP, GO, NODEJS, HASK, SCALA, D, PERL, FORT, WSPC, ADA, CAML, ICK, BF, ASM, CLPS, PRLG, ICON, SCM qobi, PIKE, ST, NICE, LUA, BASH, NEM, LISP sbcl, LISP clisp, SCM guile, JS, ERL, TCL, PERL6, TEXT, CLOJ, FS|
Fetching successful submissions
If you are still having problems, see a sample solution here.