poj3414

 

题目好像是模拟水桶来回倒的问题，full就是倒满，drop就是全倒掉，pour就是从一个通去另一个桶，今天poj还是502.。。也不知道写的对不对，但样例过了。。嗯，就那一个样例Orz。。。。模拟一下暴力解决就行了，不过回头改。。。

 

警告！！！没有A！！！虽然我找了半天没找到错在哪里。。

#include<iostream>
#include<cstring>
#include<queue>
#include<stack>
using namespace std;
struct pot
{
    int x1,x2,time,pre,location;string op;
    void init(int xx1,int xx2,int t,int p,int l,string o)
    {
        x1=xx1;x2=xx2;time=t;pre=p;location=l;op=o;
    }
};
pot q[10005];
bool book[105][105];
int a,b,c,head=0,tail=0;
void push(pot temp)
{
    q[tail++]=temp;
}
pot pop()
{
    pot temp=q[head++];
    return temp;
}

int bfs()
{
    pot t;
    t.init(0,0,0,-1,0,"null");
    book[t.x1][t.x2]=1;
    push(t);
    while(head!=tail)
    {
        pot temp=pop();
        if(temp.x1==c||temp.x2==c)return temp.location;
        //full 1
        if(!book[a][temp.x2])
        {
            pot p;p.init(a,temp.x2,temp.time+1,temp.location,tail,"FILL(1)");
            book[a][temp.x2]=1;
            push(p);
        }
        //full 2
         if(!book[temp.x1][b])
        {
            pot p;p.init(temp.x1,b,temp.time+1,temp.location,tail,"FILL(2)");
            book[temp.x1][b]=1;
            push(p);
        }
        //drop 1
        if(!book[0][temp.x2])
        {
            book[0][temp.x2];
            pot p;p.init(0,temp.x2,temp.time+1,temp.location,tail,"DROP(1)");
            push(p);
        }
        //drop 2
        if(!book[temp.x1][0])
        {
            book[temp.x1][0]=1;
            pot p;p.init(temp.x1,0,temp.time+1,temp.location,tail,"DROP(1)");
            push(p);
        }
        //pour 2-1
        int r1=a-temp.x1;
        if(r1>temp.x2)//可以全部装进去
        {
            if(!book[temp.x1+temp.x2][0])
            {
                book[temp.x1+temp.x2][0]=1;
                pot p;p.init(temp.x1+temp.x2,0,temp.time+1,temp.location,tail,"POUR(2,1)");
                push(p);
            }
        }
        else if(r1>0)
        {
            if(!book[a][temp.x2-r1])
            {
                book[a][temp.x2-r1]=1;
                pot p;p.init(a,temp.x2-r1,temp.time+1,temp.location,tail,"POUR(2,1)");
                push(p);
            }
        }
        int r2=b-temp.x2;
        if(r2>temp.x1)//可以全部装进去
        {
            if(!book[0][temp.x2+temp.x1])
            {
                book[0][temp.x2+temp.x1]=1;
                pot p;p.init(0,temp.x2+temp.x1,temp.time+1,temp.location,tail,"POUR(1,2)");
                push(p);
            }
        }
        else if(r2>0)
        {
            if(!book[temp.x1-r2][b])
            {
                book[temp.x1-r2][b]=1;
                pot p;p.init(temp.x1-r2,b,temp.time+1,temp.location,tail,"POUR(1,2)");
                push(p);
            }
        }
    }
    return -1;
}
void print()
{
    int k=bfs();
    if(k<0)cout<<"Impossible"<<endl;
    else
    {
        cout<<q[k].time<<endl;
        stack<string>s;
        while(k!=0)
        {
            string temp=q[k].op;
            s.push(temp);
            k=q[k].pre;
        }
        while(!s.empty())
        {
            string temp=s.top();
            cout<<temp<<endl;
            s.pop();
        }
    }
}
int main()
{
    cin>>a>>b>>c;
    print();
    return 0;
}