[Number Theory] [maximum public approx.] [enumeration approx.] codevs 1012 maximum public approx. and minimum public I issues in 2001 noip National League popularity Group

For a pair of numbers (p, q), if their GCD is x0 and the LCM is y0,

P * q/X0 = y0, that is, q = x0 * Y0/P,

Since p and q are positive integers, p and q must all be x0 * y0 divisor.

Therefore, the O (SQRT (x0 * y0) enumerated approx. It is determined by GCD in sequence.

1 # include <cstdio> 2 # include <cmath> 3 using namespace STD; 4 typedef long ll; 5 ll limit, Q, P, to; 6 int ans; 7 LL gcd (ll a, LL B) {return B = 0? A: gcd (B, A % B);} 8 int main () 9 {10 scanf ("% d", & P, & Q ); limit = p * q; 11 to = SQRT (Limit); 12 for (ll I = P; I <= to; I ++) 13 if (Limit % I = 0) 14 if (gcd (I, limit/I) = P) 15 ans ++; 16 printf ("% d \ n ", ans <1); 17 return 0; 18}

 

[Number Theory] [maximum public approx.] [enumeration approx.] codevs 1012 maximum public approx. and minimum public I issues in 2001 noip National League popularity Group