Romantic hd 2669

Problem Description The Sky is Sprite. The Birds is Fly in the Sky. The Wind is Wonderful. Blew Throw the Trees Trees are Shaking, Leaves are Falling. Lovers Walk passing, and so are You. ................................Write in English class by yifenfei Girls are clever and bright. In HDU every girl like math. Every girl like to solve math problem! Now tell you two nonnegative integer a and b. Find the nonnegative integer X and integer Y to satisfy X*a + Y*b = 1. If no such answer print "sorry" instead. Input The input contains multiple test cases. Each case two nonnegative integer a,b (0<a, b<=2^31) Output output nonnegative integer X and integer Y, if there are more answers than the X smaller one will be choosed. If no answer put "sorry" instead. Sample Input 77 51 10 44 34 79 Sample Output 2 -3 sorry

7 -3

#include<cstdio> #include<cmath> long long e_gcd(long long a,long long b,long long &x,long long &y) { if(b==0) { x=1; y=0; return a; } long long ans=e_gcd(b,a%b,x,y); long long temp=x; x=y; y=temp-a/b*y; return ans; } long long cal(long long a,long long b,long long c) { long long x,y; long long gcd=e_gcd(a,b,x,y); if(c%gcd!=0) return -1; x*=c/gcd; b/=gcd; if(b<0) b=-b; long long ans=x%b; if(ans<=0) ans+=b; return ans; } int main() { long long a,b; while(scanf("%I64d%I64d",&a,&b)!=EOF) { long long ans=cal(a,b,1); if(ans==-1) printf("sorry\n"); else printf("%I64d %I64d\n",ans,(1-ans*a)/b); } return 0; }