模板—数学—Exgcd

模板—数学—Exgcd

Code:

#include <cstdio>
#include <algorithm>
using namespace std;
int ex_gcd(int a,int b,int &x,int &y)
{
	if(!b) {x=1,y=0;return a;}
	int gcd=ex_gcd(b,a%b,x,y),tmp=x;
	x=y,y=tmp-a/b*y; return gcd;
}
int a,b,c,gcd,x1,y1;
int main()
{
	scanf("%d%d%d",&a,&b,&c),gcd=ex_gcd(a,b,x1,y1);
	if(c%gcd) {printf("-1
");return 0;}
	x1*=c/gcd,y1*=c/gcd;
	printf("x=%d+k*%d
",x1,b/gcd);
	printf("y=%d-k*%d
",y1,a/gcd);
}