同余方程
[Time Gate]
https://www.luogu.org/problemnew/show/P1082
[解题思路】
推荐一个不错的写扩欧的博客
https://www.zybuluo.com/samzhang/note/541890
这是一道扩欧模板题
【code】
1 #include <cstdio> 2 #include <iostream> 3 #include <algorithm> 4 using namespace std; 5 int a,b,res,ans,x,y; 6 inline void exEuclid_Algorithm(int a,int b,int &x,int &y){ 7 if(b!=0){ 8 exEuclid_Algorithm(b,a%b,y,x); 9 y-=a/b*x; 10 } 11 else { 12 x=1; 13 y=0; 14 return ; 15 } 16 } 17 int main(){ 18 //freopen("1082.in","r",stdin); 19 //freopen("1082.out","w",stdout); 20 scanf("%d%d",&a,&b); 21 /*while(res!=1){ 22 ans++; 23 res=res+a; 24 if(res>b)res%=b; 25 } 26 printf("%lld\n",ans);*/ 27 exEuclid_Algorithm(a,b,x,y); 28 printf("%d\n",(x%b+b)%b); 29 return 0; 30 }
