題目學習——HDUOJ-2669

Romantic

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)

Problem Description

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

 

Author

yifenfei

#include <iostream>
#include <cstdio>
#define LL long long int
using namespace std;

LL e_gcd(LL a,LL b,LL &x,LL &y)
{
    if(b==0){
        x=1;
        y=0;
        return a;
    }
    LL ans=e_gcd(b,a%b,x,y);
    LL temp=x;
    x=y;
    y=temp-a/b*y;
    return ans;
}
LL inv(LL a,LL m,LL c)
{
    LL x,y;
    LL gcd=e_gcd(a,m,x,y);
    if(c%gcd!=0)return -1;
    m=c/gcd*m;
    if(m<0)m=-m;
    LL ans=x%m;
    if(ans<=0)ans=ans+m;
    return ans;
}


int main()
{
    LL a,b,x,y,ans;
    while(scanf("%lld%lld",&a,&b)!=EOF){
        if((ans=inv(a,b,1))!=-1)printf("%lld %lld\n",ans,(1-ans*a)/b);
        else printf("sorry\n");
    }
    return 0;
}