hdu 2216 Game III BFS

这道题有个错误就是输入时必须得用gets()或者scanf("%s")

/*
    HDU2216    15ms 812k
*/
#include<iostream>
#include<algorithm>
#include<queue>
#define N 22
#define ANAL -1
using namespace std;

int stepx[]={0,1,-1,0};
int stepy[]={1,0,0,-1};
int zx,zy,sx,sy;//对应z和s的开始坐标
int n,m;
char map[N][N];
int dist[N][N][N][N];//存储当前(BFS例程中)z到s的长度
bool check(int zx,int zy,int sx,int sy)//检查是Z否与S相邻(x+y=1)或重合(x+y=0)
{
    int x,y;
    x=abs(zx-sx);
    y=abs(zy-sy);
    if(x+y<2)
        return true;
    else
        return false;
}

int BFS()
{
    queue<int>Q;
    int tzx,tzy,tzx2,tzy2;
    int tsx,tsy,tsx2,tsy2;
    if(check(zx,zy,sx,sy))
        return 0;
    
    Q.push(zx);
    Q.push(zy);
    Q.push(sx);
    Q.push(sy);
    while(!Q.empty())
    {
        tzx=Q.front();Q.pop();
        tzy=Q.front();Q.pop();
        tsx=Q.front();Q.pop();
        tsy=Q.front();Q.pop();
        for(int i=0;i<4;i++)
        {
            tzx2=tzx+stepx[i];
            tzy2=tzy+stepy[i];

            if(!(map[tzx2][tzy2]=='.'))
                continue;
            tsx2=tsx-stepx[i];
            tsy2=tsy-stepy[i];
            if(!(map[tsx2][tsy2]=='.')) {tsx2=tsx;tsy2=tsy;}
            if(check(tzx2,tzy2,tsx2,tsy2))
                return dist[tzx][tzy][tsx][tsy]+1;
            if(dist[tzx2][tzy2][tsx2][tsy2]!=-1)
                continue;
            Q.push(tzx2);
            Q.push(tzy2);
            Q.push(tsx2);
            Q.push(tsy2);
            dist[tzx2][tzy2][tsx2][tsy2]=dist[tzx][tzy][tsx][tsy]+1;
        }
    }
    while(!Q.empty())
        Q.pop();
    return -1;
}
void Init()//初始化，这里有个技巧，就是map下标从1开始使用，目的是为了在图的周围围成一圈墙，省去每次判断坐标是否越界
{
    memset(map,'X',sizeof(map));//围墙
    memset(dist,-1,sizeof(dist));//距离初始化
    getchar();
    for(int i=1;i<=n;i++)
    {
        gets(map[i]+1);
        for(int j=1;j<=m;j++)
        {            
            if(map[i][j]=='Z'){zx=i;zy=j;map[i][j]='.';}
            else if(map[i][j]=='S'){sx=i;sy=j;map[i][j]='.';}
        }
    }
    dist[zx][zy][sx][sy]=0;//起点
}
int main()
{
    while(scanf("%d%d",&n,&m)!=EOF)
    {
        Init();
        int res;
        res = BFS();
        if(res==-1)
            puts("Bad Luck!");
        else
            printf("%d\n",res);
    }

    return 0;
}

 

几个测试数据：

 

2 2
Z.
.S

4 4
.Z..
.X..
....
XS..

4 4
.Z..
.X..
....
.SXX

4 4
X..S
..X.
.X..
.Z..

4 4
X..S
....
.X..
.Z..