邝斌的ACM模板（模线性方程组）

本博客整理自邝斌的ACM模板
2.5、模线性方程组

long long extend_gcd(long long a,long long b,long long &x,long long  &y){    if(a == 0 && b == 0)return -1;    if(b ==0 )    {        x = 1;        y = 0;        return a;    }    long long d = extend_gcd(b,a%b,y,x);    y -= a/b*x;    return d;}int m[10],a[10];//模数为m,余数为a, X % m = abool solve(int &m0,int &a0,int m,int a){    long long y,x;    int g = extend_gcd(m0,m,x,y);    if( abs(a - a0)%g )return false;    x *= (a - a0)/g;    x %= m/g;    a0 = (x*m0 + a0);    m0 *= m/g;    a0 %= m0;    if( a0 < 0 )a0 += m0;    return true;}/* * 无解返回false,有解返回true; * 解的形式最后为 a0 + m0 * t  (0<=a0<m0) */bool MLES(int &m0,int &a0,int n) //解为  X = a0 + m0 * k{    bool flag = true;    m0 = 1;    a0 = 0;    for(int i = 0; i < n; i++)                 if( !solve(m0,a0,m[i],a[i]) )        {            flag = false;            break;        }    return flag;}