Sereja and GCD
All submissions for this problem are available.
Read problems statements in Mandarin Chinese and Russian.
In this problem Sereja is interested in the number of arrays of integers, A1, A2, ..., AN, with 1 ≤ Ai ≤ M, such that the greatest common divisor of all of its elements is equal to a given integer D.
Find the sum of answers to this problem with D = L, D = L+1, ..., D = R, modulo 109+7.
The first line of the input contains an integer T - the number of test cases. T tests follow, each containing a single line with the values of N, M, L, R.
For each test case output the required sum, modulo 109+7.
- 1 ≤ T ≤ 10
- 1 ≤ L ≤ R ≤ M
- Subtask #1: 1 ≤ N, M ≤ 10 (10 points)
- Subtask #2: 1 ≤ N, M ≤ 1000 (30 points)
- Subtask #3: 1 ≤ N, M ≤ 107 (60 points)
Input: 2 5 5 1 5 5 5 4 5 Output: 3125 2
|Tags||dec14, medium, number-theory, sereja|
|Time Limit:||1 - 15 sec|
|Source Limit:||50000 Bytes|
|Languages:||C, CPP14, JAVA, PYTH, PYTH 3.6, 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, PYP3, CLOJ, FS|
Fetching successful submissions
If you are still having problems, see a sample solution here.