#include<iostream>
using namespace std;
class ModularLinearSolver//这个类解线性同余方程
{
private:
	long x,y,m,n,l;
public:
	long ext_euclid(long a,long b,long &x,long &y);
	void modularSolver(long a, long b, long n);
	long mod(long a,long b);
};

/******************************************** 

      求解模线性方程 ax=b (mod n) ,n>0 

*********************************************/ 
void ModularLinearSolver::modularSolver(long a, long b, long n) 
{ 
   long e,i,d; 
   long x,y; 
   d = ext_euclid(a, n, x, y); 
   if (b%d==0) 
   { 
	    e=(x*(b/d))%n;
        cout<<mod(x*(b/d),n/d)<<endl;
   }
   else 
   {  
       cout<<"Impossible"<<endl; 
   } 
} 
/********************************************* 

    扩展欧几里德算法求gcd(a,b)=ax+by 

*********************************************/ 
long ModularLinearSolver::ext_euclid(long a,long b,long &x,long &y) 
{ 
   long t,d; 
   if (b==0)
   {
	   x=1;y=0;return a;
   } 
   d=ext_euclid(b,a%b,x,y); 
   t=x; 
   x=y; 
   y=t-a/b*y; 
   return d; 
} 
long ModularLinearSolver::mod(long a,long b)
{
if(a >= 0)
      return a % b;
else
      return a % b + b;
}
int main()
{
	long x,y,m,n,l;
	ModularLinearSolver solver;
	cin>>x>>y>>m>>n>>l;
	solver.modularSolver(n-m,x-y,l);
    return 0;
}

• Re:大家看看到底哪里错了的嘛 运行没错啊 (1414) mogen 2010-04-10 10:55:00