> #include <iostream>
> #include <vector>
> #include <queue>
> using namespace std;
> bool v[110][110];
> int a,b,c;
> struct pot
> {
> 	int a,b;
> 	vector<pair<int,int> >vec;//记录路径,,pour(1,2)记为(1,2),drop(1)记为(1,4),fill(1)记为(1,3)
> 	pot(int aa,int bb):a(aa),b(bb){}
> };
> void output(vector<pair<int,int> >&vec)
> {
> 	cout<<vec.size()-1<<endl;
> 	int i;
> 	for(i=1;i<vec.size();i++)
> 	{
> 		if(vec[i].second==3)
> 			cout<<"FILL("<<vec[i].first<<')'<<endl;
> 		else if(vec[i].second==4)
> 			cout<<"DROP("<<vec[i].first<<')'<<endl;
> 		else
> 			cout<<"POUR("<<vec[i].first<<','<<vec[i].second<<')'<<endl;
> 	}
> }
> int main()
> {
> 	cin>>a>>b>>c;
> 	memset(v,false,sizeof(v));
> 	v[0][0]=true;
> 	pot temp(0,0);
> 	temp.vec.push_back(pair<int,int>(0,0));
> 	queue<pot>q;
> 	q.push(temp);
> 	while(!q.empty())
> 	{
> 		temp=q.front();
> 		q.pop();
> 		if(temp.a==c||temp.b==c)
> 		{
> 			output(temp.vec);
> 			return 0;
> 		}
> 		if(!v[temp.a][b])
> 		{
> 			v[temp.a][b]=true;
> 			pot p(temp);
> 			p.b=b;
> 			p.vec.push_back(pair<int,int>(2,3));
> 			q.push(p);
> 		}
> 		if(!v[a][temp.b])
> 		{
> 			v[a][temp.b]=true;
> 			pot p(temp);
> 			p.a=a;
> 			p.vec.push_back(pair<int,int>(1,3));
> 			q.push(p);
> 		}
> 		int aa=temp.a+temp.b,bb=0;
> 		if(aa>a)
> 		{
> 			bb=aa-a;
> 			aa=a;
> 		}
> 		if(!v[aa][bb])
> 		{
> 			v[aa][bb]=true;
> 			pot p(temp);
> 			p.a=aa,p.b=bb;
> 			p.vec.push_back(pair<int,int>(2,1));
> 			q.push(p);
> 		}
> 		aa=0,bb=temp.a+temp.b;
> 		if(bb>b)
> 		{
> 			aa=bb-b;
> 			bb=b;
> 		}
> 		if(!v[aa][bb])
> 		{
> 			v[aa][bb]=true;
> 			pot p(temp);
> 			p.a=aa,p.b=bb;
> 			p.vec.push_back(pair<int,int>(1,2));
> 			q.push(p);
> 		}
> 		if(!v[temp.a][0])
> 		{
> 			v[temp.a][0]=true;
> 			pot p(temp);
> 			p.b=0;
> 			p.vec.push_back(pair<int,int>(2,4));
> 			q.push(p);
> 		}
> 		if(!v[0][temp.b])
> 		{
> 			v[0][temp.b]=true;
> 			pot p(temp);
> 			p.a=0;
> 			p.vec.push_back(pair<int,int>(1,4));
> 			q.push(p);
> 		}
> 	}
> 	cout<<"impossible"<<endl;
> 	return 0;
> }


我怒了！~C++为什么有STL~~！~