POJ3414(BFS+[手写队列])

贴一发自己写的手写队列…..

#include <stdio.h>
#include <iostream>
#include <string.h>
#include <math.h>
#include <stdlib.h>
#include <queue>
#include <set>
#include <stack>
#include <algorithm>
using namespace std;
#define PI acos(-1.0)
#define INF 0x7fffffff
#define N 1010
struct asd
{
    int a,b;
    int flag;
    int step;
} q[N];
int pre[N];
int vis[N][N];
int head,rail;
void pri()
{
    printf("impossible\n");
}
void print(int x)
{
    int t;
    t=pre[x];
    if(t==0)
    {
        if(q[x].flag==0)
        {
            printf("FILL(1)\n");
        }
        else if(q[x].flag==1)
        {
            printf("FILL(2)\n");
        }
        else if(q[x].flag==2)
        {
            printf("DROP(1)\n");
        }
        else if(q[x].flag==3)
        {
            printf("DROP(2)\n");
        }
        else if(q[x].flag==4)
        {
            printf("POUR(2,1)\n");
        }
        else if(q[x].flag==5)
        {
            printf("POUR(1,2)\n");
        }
        return;
    }
    else
    {
        print(t);
    }

    if(q[x].flag==0)
    {
        printf("FILL(1)\n");
    }
    else if(q[x].flag==1)
    {
        printf("FILL(2)\n");
    }
    else if(q[x].flag==2)
    {
        printf("DROP(1)\n");
    }
    else if(q[x].flag==3)
    {
        printf("DROP(2)\n");
    }
    else if(q[x].flag==4)
    {
        printf("POUR(2,1)\n");
    }
    else if(q[x].flag==5)
    {
        printf("POUR(1,2)\n");
    }
}

void bfs(int n,int m,int c)
{
    memset(vis,0,sizeof(vis));
    head=0;
    rail=1;
    q[0].a=0;
    q[0].b=0;
    q[0].flag=-1;
    q[0].step=0;
    vis[0][0]=1;
    pre[0]=-1;
    while(head<rail)
    {
        //printf("%d\n",head);
        int x=q[head].a;
        int y=q[head].b;
        if(x==c||y==c)
        {
            printf("%d\n",q[head].step);
            print(head);
            return;
        }
        for(int i=0; i<6; i++)
        {
            if(i==0)
            {
                q[rail].a=n;
                q[rail].b=q[head].b;
                q[rail].flag=0;
            }
            else if(i==1)
            {
                q[rail].a=q[head].a;
                q[rail].b=m;
                q[rail].flag=1;
            }
            else if(i==2)
            {
                q[rail].a=0;
                q[rail].b=q[head].b;
                q[rail].flag=2;
            }
            else if(i==3)
            {
                q[rail].a=q[head].a;
                q[rail].b=0;
                q[rail].flag=3;
            }
            else if(i==4)
            {
               // printf("aaa\n");
                if((q[head].b+q[head].a)>=n)
                {
                    q[rail].a=n;
                    q[rail].b=q[head].b-(n-q[head].a);
                    q[rail].flag=4;
                }
                else if((q[head].b+q[head].a)<n)
                {
                    q[rail].a=q[head].a+q[head].b;
                    q[rail].b=0;
                    q[rail].flag=4;
                }
               // printf("%d %d\n",q[rail].a,q[rail].b);
            }
            else if(i==5)
            {
                if((q[head].a+q[head].b)>=m)
                {
                    q[rail].a=q[head].a-(m-q[head].b);
                    q[rail].b=m;
                    q[rail].flag=5;
                }
                else if((q[head].a+q[head].b)<m)
                {
                    q[rail].a=0;
                    q[rail].b=q[head].b+q[head].a;
                    q[rail].flag=5;
                }
            }
            //printf("%d %d\n",q[rail].a,q[rail].b);
            if(vis[q[rail].a][q[rail].b])
                continue;
            vis[q[rail].a][q[rail].b]=1;
            q[rail].step=q[head].step+1;
            pre[rail]=head;
            rail++;
            if(q[rail].b==c||q[rail].a==c)
            {
                //printf("aaa\n");
                printf("%d\n",q[head].step+1);
                print(rail);
                return;
            }
        }
        head++;
    }
    pri();
    return;
}
int main()
{
    int n,m,c;
    while(~scanf("%d%d%d",&n,&m,&c))
    {
       // printf("%d %d %d\n",n,m,c);
        bfs(n,m,c);
    }
    return 0;
}