FNRANK - Rank of a Fraction
Let us consider a set of fractions x/y, such that 0 <= x/y <= 1, y <= n and gcd (x, y) = 1.
For example, say n = 5. Then we have the following set in increasing order :
0⁄1, 1⁄5, 1⁄4, 1⁄3, 2⁄5, 1⁄2, 3⁄5, 2⁄3, 3⁄4, 4⁄5, 1⁄1
You are given n, a and b. The task is to find the rank of a/b in a set of fractions as stated above which is in increasing order.
The first line of the input contains t (t <= 20), the number of testcases. Then t lines follow. In each of the t lines you are given n, a and b. (n <= 100000)
Print t lines. The ith line contains the rank of a fraction a/b for a given n, a and b in the (i + 1)th line of input. All answers fit within a signed integer.
5 3 4
8 5 7
Use of inclusion and exclusion property!!
use long long costed 10WA
Let's get to all X from 1 to N and check how many Y/X are there who are less than A/B and gcd(X, Y)=1. To do this,
am using the the formula to generate its next numbers but still tle:(