问题描述

关于农夫问题的C语言解决

以下代码输出为no solutin.，请问错在哪里？

 #include<stdio.h>
#include<stdlib.h>
struct seqqueue
{
    int maxnum;
    int f,r;
    int *data;
};
int main()
{
    struct seqqueue *createemptyqueue_seq(int m);
    void enqueue_seq(struct seqqueue *p,int x);
    void dequeue_seq(struct seqqueue *p);
    int frontqueue_seq(struct seqqueue *p);
    int isemptyqueue_seq(struct seqqueue *hq);
    int farmer(int location);
    int wolf(int location);
    int cabbage(int location);
    int goat(int location);
    int safe(int location);
    void farmerproblem();
    farmerproblem();
    return 0;
}
struct seqqueue *createemptyqueue_seq(int m)             //创建空队列
{
    struct seqqueue *p=(struct seqqueue*)malloc(sizeof(struct seqqueue));
    if(p!=NULL)
    {
        p->maxnum=m;
        p->data=(int*)malloc(sizeof(int)*p->maxnum);
        if(p->data)
        {
            p->f=p->r=0;
            return p;
        }
        else
        {
            free(p);
        }
    }
    printf("out of space!");
    return NULL;
}
void enqueue_seq(struct seqqueue *p,int x)          //入队
{
    if((p->r+1)%p->maxnum==p->f)
        printf("full queue.");
    else
    {
        p->data[p->r]=x;
        p->r=(p->r+1)%p->maxnum;
    }
}
void dequeue_seq(struct seqqueue *p)                     //出队
{
    if(p->f==p->r)
        printf("empty queue!");
    else
        p->f=(p->f+1)%p->maxnum;
}
int frontqueue_seq(struct seqqueue *p)              //取队列的头元素
{
    if(p->f==p->r)
        printf("empty queue!");
    else
        return (p->data[p->f]);
}
int isemptyqueue_seq(struct seqqueue *q)
{                                                   //判断队首或队尾任一个指针是否为空即可
    if(q->r==q->f)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}
int farmer(int location)         //判断农夫的位置
{
    return (0!=(location&0x08));
}
int wolf(int location)            //判断狼的位置
{
    return (0!=(location&0x04));
}
int cabbage(int location)          //判断白菜的位置
{
    return (0!=(location&0x02));
}
int goat(int location)             //判断羊的位置
{
    return (0!=(location&0x01));
}
int safe(int location)             //安全状态判断函数
{
    if((goat(location)==cabbage(location))&&(goat(location)!=farmer(location)))
        return 0;
    if((goat(location)==wolf(location))&&(goat(location)!=farmer(location)))
        return 0;
    return 1;
}
void farmerproblem()
{
    int i,movers,location,newlocation;
    int route[16];
    struct seqqueue *moveto;
    moveto=createemptyqueue_seq(17);
    enqueue_seq(moveto,0x00);
    for(i=0;i<16;i++)
        route[i]=-1;
    route[0]=0;
    while(!isemptyqueue_seq(moveto)&&(route[15]==-1))
    {
        location=frontqueue_seq(moveto);
        dequeue_seq(moveto);
        for(movers=1;movers<=8;movers<<=1)
            if((0!=(location&0x08))==(0!=(location&movers)))
            {
                newlocation=location^(0x00|movers);
                if(safe(newlocation)&&(route[newlocation]==-1))
                {
                    route[newlocation]=location;
                    enqueue_seq(moveto,newlocation);
                }
            }
    }
    if(route[15]!=-1)
    {
        printf("the revers path is:n");
        for(location=15;location>=0;location=route[location])
        {
            printf("the location is:%dn",location);
            if(location==0)exit(0);
        }
    }
    else printf("no solution.n");
}

解决方案

这行错了
newlocation=location^(0x00|movers);
修改
newlocation=location^(0x08|movers);

解决方案二：

http://blog.sina.com.cn/s/blog_50d936c40100e2wl.html

解决方案三：

http://blog.csdn.net/jamesjxin/article/details/6891188

解决方案四：

newlocation=location^(0x00|movers);
修改
newlocation=location^(0x08|movers);