HDU1573 X问题

//It is made by ljh2000
//有志者，事竟成，破釜沉舟，百二秦关终属楚；苦心人，天不负，卧薪尝胆，三千越甲可吞吴。
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <ctime>
#include <vector>
#include <queue>
#include <map>
#include <set>
#include <string>
#include <complex>
#include <bitset>
using namespace std;
typedef long long LL;
typedef long double LB;
typedef complex<double> C;
const double pi = acos(-1);
const int MAXN = 12;
int n,k,m[MAXN],r[MAXN],ans;

inline int getint(){
int w=0,q=0; char c=getchar(); while((c<'0'||c>'9') && c!='-') c=getchar();
if(c=='-') q=1,c=getchar(); while (c>='0'&&c<='9') w=w*10+c-'0',c=getchar(); return q?-w:w;
}

inline void exgcd(int a,int b,int &d,int &x,int &y){
if(b==0) { d=a; x=1; y=0; return ; }
exgcd(b,a%b,d,y,x);
y-=a/b*x;
}

inline void work(){
int T=getint();
while(T--) {
n=getint(); k=getint();
for(int i=1;i<=k;i++) m[i]=getint();
for(int i=1;i<=k;i++) r[i]=getint();
int M=m[1],R=r[1],d,x,y,z,b;
bool ok=false;
for(int i=2;i<=k;i++) {
exgcd(M,m[i],d,x,y);
z=r[i]-R; if(z%d!=0) { ok=true; break; }
b=m[i]; b/=d; z/=d;
x=x*z%b; x+=b; x%=b;
R+=x*M;
M=M*m[i]/d;
}
if(ok || n<R) { puts("0"); continue; }
ans=(n-R)/M; ans++;
if(R==0) ans--;//!!!
printf("%d\n",ans);
}
}

int main()
{
work();
return 0;
}
//有志者，事竟成，破釜沉舟，百二秦关终属楚；苦心人，天不负，卧薪尝胆，三千越甲可吞吴。