The greatest common divisor GCD(a,b) of two positive integers a and b,sometimes written (a,b),is the largest divisor common to a and b,For example,(1,2)=1,(12,18)=6.
(a,b) can be easily found by the Euclidean algorithm. Now Carp is considering a little more difficult problem: Given integers N and M, how many integer X satisfies 1<=X<=N and (X,N)>=M.Input
The first line of input is an integer T(T<=100) representing the number of test cases. The following T lines each contains two numbers N and M (2<=N<=1000000000, 1<=M<=N), representing a test case.
Output
For each test case,output the answer on a single line.
Sample Input
31 110 210000 72
Sample Output
16260
代码:
#include#include #include #include using namespace std;long long int oula(int n){ long long int res=1; for(int t=2;t*t<=n;t++) { if(n%t==0) { n/=t; res*=t-1; while(n%t==0) { n/=t; res*=t; } } } if(n>1) { res*=n-1; } return res;}int main(){ int n; cin>>n; int a,b; long long int ans; for(int t=0;t =b) { ans+=oula(a/j); } if(a/j>=b) { ans+=oula(j); } } } if(j*j==a&&j>=b) { ans+=oula(j); } cout< <