【模板】有理数取余
【TIMEGate】
https://www.luogu.org/problem/P2613
【解题思路】
扩欧数学
【code】
1 #include <cstdio>
2 #include <algorithm>
3 #include <iostream>
4 using namespace std;
5 const int mod=19260817;
6 long long a,b;
7 int x,y;
8 inline void read(long long &x){
9 int f=1;x=0;char s=getchar();
10 while(s>'9'||s<'0'){
11 if(s=='-')f=-1;
12 s=getchar();
13 }
14 while(s<='9'&&s>='0'){
15 x=x*10%mod+(s-'0')%mod;
16 s=getchar();
17 }
18 x=x%mod*f;
19 }
20 inline void Exgcd(int a,int b,int &x,int &y){
21 if(b==0){
22 x=1;
23 y=0;
24 return ;
25 }
26 Exgcd(b,a%b,x,y);
27 int x2=x,y2=y;
28 x=y2;
29 y=x2-(a/b)*y2;
30 }
31 int main(){
32 read(a),read(b);
33 if(b==0){
34 printf("Angry!\n");
35 return 0;
36 }
37 Exgcd(b,mod,x,y);
38 x=(x%mod+mod)%mod;
39 printf("%lld\n",(long long)x*a%mod);
40 while(1);
41 return 0;
42 }
