HDU 2669 Romantic 扩展欧几里得模板题@

Romantic

Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u

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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 5110 4434 79

Sample Output

2 -3sorry7 -3

求ax+by=1的最小解

#include <iostream>#include <cstdio>#include <cstring>#include <cmath>using namespace std;typedef long long LL;LL ex_gcd(LL a,LL b,LL &x,LL &y);LL cal(LL a,LL b);LL s1, s2;int main(){    LL m, n;    while(scanf("%I64d %I64d", &m, &n)!=EOF)    {        LL ans=cal(m,n);        if(ans==-1)   printf("sorry\n");        else   printf("%I64d %I64d\n",s1, s2);    }    return 0;}LL cal(LL a,LL b){    LL x, y;    LL gcd=ex_gcd(a,b,x,y);    if(1%gcd!=0)  return -1;    x*=1/gcd;    b/=gcd;    if(b<0) b=-b;    s1=x%b;    if(s1<0)   s1+=b;    s2=(1-a*s1)/b;    return 1;}LL ex_gcd(LL a,LL b,LL &x,LL &y){    if(b==0)    {        x=1;        y=0;        return a;    }    LL ans=ex_gcd(b,a%b,x,y);    LL tmp=x;    x=y;    y=tmp-a/b*y;    return ans;}