hdu 1573 X问题 （中国剩余定理）

#include 
#include 
#define ll long long
using namespace std;
long long a[15],b[15];
long long gcd(long long a,long long b)
{
    return b==0?a:gcd(b,a%b);
}

long long ex_gcd(long long a,long long b,long long &x,long long &y)
{
    if(b==0)
    {
        x=1;
        y=0;
        return a;
    }
    long long ans;
    ans=ex_gcd(b,a%b,x,y);
    long long t;
    t=x;
    x=y;
    y=t-(a/b)*y;
    return ans;
}
ll china( ll m,ll n)  //下标[l,r] 方程x%m=a;
{
    for(int i=2; i<=m; i++)
    {
        ll A = a[1], B = a[i], d, x, y, c = b[i]-b[1];
       d=ex_gcd(A,B,x,y);
        if(c%d)return 0;
        ll mod = a[i]/d;
        ll K = ((x*c/d)%mod+mod)%mod;
        b[1] = a[1]*K + b[1];
        a[1] = a[1]*a[i]/d;
    }
    b[1]=(b[1]+a[1])%a[1];
    if(b[1]>n)return 0;
     return (n-b[1])/a[1]+1-(b[1]==0?1:0);//要求正整数 减去0
}

int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        long long n;
        int m;
        cin>>n>>m;
        for(int i=1; i<=m; i++)
            cin>>a[i];
        for(int i=1; i<=m; i++)
            cin>>b[i];
        cout<