ACM | Assignments 6

7-2 非常可乐

大家一定觉的运动以后喝可乐是一件很惬意的事情，但是seeyou却不这么认为。因为每次当seeyou买了可乐以后，阿牛就要求和seeyou一起分享这一瓶可乐，而且一定要喝的和seeyou一样多。但seeyou的手中只有两个杯子，它们的容量分别是N 毫升和M 毫升 可乐的体积为S （S<101）毫升　(正好装满一瓶) ，它们三个之间可以相互倒可乐 (都是没有刻度的，且 S==N+M，101＞S＞0，N＞0，M＞0) 。聪明的ACMER你们说他们能平分吗？如果能请输出倒可乐的最少的次数，如果不能输出"NO"。

输入格式:

三个整数 : S 可乐的体积 , N 和 M是两个杯子的容量，以"0 0 0"结束。

输出格式:

如果能平分的话请输出最少要倒的次数，否则输出"NO"。

输入样例:

7 4 3
4 1 3
0 0 0

输出样例:

NO
3

Code

WA代码

#include<bits/stdc++.h>
using namespace std;

struct State{
    int s,a,b;
    int step;
};

bool used[105][105][105];

int bfs(int s,int a,int b){
    if(s%2==1)
        return -1;
    queue<State> q;
    State now;
    now.s=s;
    now.a=0;
    now.b=0;
    now.step=0;
    q.push(now);
    while(!q.empty()){
        now=q.front();
        q.pop();
        cout<<now.s<<" "<<now.a<<" "<<now.b<<" "<<now.step<<endl;
        // if(used[now.s][now.a][now.b])
        //     continue;
        // if(now.a==s/2 || now.b==s/2 || now.s==s/2)
        if((now.a==s/2 && now.b==s/2)||(now.a==s/2 && now.s==s/2)||(now.s==s/2 && now.b==s/2))
            return now.step;
            
        used[now.s][now.a][now.b]=true;
        State newstate;
        newstate.step=now.step+1;
        
        //S->A
        if(now.s>=a-now.a){
            newstate.s=now.s-(a-now.a);
            newstate.a=now.a+(a-now.a);
            newstate.b=now.b;
            if(!used[newstate.s][newstate.a][newstate.b])
                q.push(newstate);
        }
        //S->B
        if(now.s>=b-now.b){
            newstate.s=now.s-(b-now.b);
            newstate.a=now.a;
            newstate.b=now.b+(b-now.b);
            if(!used[newstate.s][newstate.a][newstate.b])
                q.push(newstate);
        }
        //A->S
        // if(now.a<s-now.s)
        {
            newstate.s=now.s+now.a;
            newstate.a=now.a-now.a;
            newstate.b=now.b;
            if(!used[newstate.s][newstate.a][newstate.b])
                q.push(newstate);
        }
        //A->B
        if(now.a<b-now.b){
            newstate.s=now.s;
            newstate.a=now.a-now.a;
            newstate.b=now.b+now.a;
            if(!used[newstate.s][newstate.a][newstate.b])
                q.push(newstate);
        }else{
            newstate.s=now.s;
            newstate.a=now.a-(b-now.b);
            newstate.b=now.b+(b-now.b);
            if(!used[newstate.s][newstate.a][newstate.b])
                q.push(newstate);
        }
        //B->S
        // if(now.b<s-now.s)
        {
            newstate.s=now.s+now.b;
            newstate.a=now.a;
            newstate.b=now.b-now.b;
            if(!used[newstate.s][newstate.a][newstate.b])
                q.push(newstate);
        }
        //B->A
        if(now.b<a-now.a){
            newstate.s=now.s;
            newstate.a=now.a+now.b;
            newstate.b=now.b-now.b;
            if(!used[newstate.s][newstate.a][newstate.b])
                q.push(newstate);
        }else{
            newstate.s=now.s;
            newstate.a=now.a+(a-now.a);
            newstate.b=now.b-(a-now.a);
            if(!used[newstate.s][newstate.a][newstate.b])
                q.push(newstate);
        }
    }
    return -1;
}

int main(){
    int s,n,m;
    while(cin>>s>>n>>m && s!=0){
        memset(used,false,sizeof(used));
        int t=bfs(s,n,m);
        if(t!=-1){
            cout<<t<<endl;
        }else{
            cout<<"NO"<<endl;
        }
    }
    
    return 0;
}

Code2

AC代码

#include<bits/stdc++.h>
using namespace std;

struct State{
    int v[3];
    int step;
};

bool used[105][105][105];

State pour(State s,int from,int to,int v[]){
    State res=s;
    res.step++;
    int temp=res.v[from]+res.v[to];
    if(temp>v[to]){
        res.v[from]=temp-v[to];
        res.v[to]=v[to];
    }else{
        res.v[to]=temp;
        res.v[from]=0;˜
    }
    return res;
}

int bfs(int s,int a,int b){
    if(s%2==1)
        return -1;
    queue<State> q;
    State now;
    int from[]={0,0,1,1,2,2};
    int to[]={1,2,0,2,0,1};
    int v[3]={s,a,b};
    now.v[0]=s;
    now.v[1]=0;
    now.v[2]=0;
    now.step=0;
    q.push(now);
    State newstate;
    while(!q.empty()){
        now=q.front();
        q.pop();

        // cout<<now.v[0]<<" "<<now.v[1]<<" "<<now.v[2]<<" "<<now.step<<endl;

        if((now.v[0]==s/2 && now.v[1]==s/2)||(now.v[0]==s/2 && now.v[2]==s/2)||(now.v[1]==s/2 && now.v[2]==s/2))
            return now.step;
            
        used[now.v[0]][now.v[1]][now.v[2]]=true;
        
        for(int i=0;i<6;i++){
            newstate=pour(now,from[i],to[i],v);
            if(!used[newstate.v[0]][newstate.v[1]][newstate.v[2]])
                q.push(newstate);
        }
    }
    return -1;
}

int main(){
    int s,n,m;
    while(cin>>s>>n>>m && s!=0){
        memset(used,false,sizeof(used));
        int t=bfs(s,n,m);
        if(t!=-1)   cout<<t<<endl;
        else   cout<<"NO"<<endl;
    }
    return 0;
}