hdu 4101 - Ali and Baba(搜索)

来源：互联网发布：array vb 编辑：程序博客网时间：2024/05/22 03:21

看起来想博弈的题目，说白了，就是一道搜索的题目。

思路：先从里往外搜，把宝藏的保护壳标记出来，如果保护壳是开口的，那么Ali第一次就能赢得比赛，如果是闭口的，那么第一次打开保护壳的人输，因此，我们再次从外围向里搜索，把那些保护壳外的都统计出来，正好在壳上的，就统计x-1，

开始的时候用的两遍dfs，果断的爆栈，然后换了bfs才过的，

还要注意存数据的数组要初始化的，，，

代码如下：

#include <cstdio>#include <cstdlib>#include <cmath>#include <cstring>#include <cstdlib>#include <stack>#include <queue>#include <vector>#include <algorithm>#include <set>#include <map>#define M 310#define INF 0x7fffffff#define eps 1e-8#define LL long longusing namespace std;struct Point{    int x, y;};int s[M][M];bool vis[M][M], flag[M][M];int n, m, cnt;int dx[] = {1,0,-1,0};int dy[] = {0,1,0,-1};int bfs(int x, int y){    Point q[M*M];    int rear = 1, pop = 0, _x, _y, _xx, _yy;    vis[x][y] = 1;    q[0] = (Point){x,y};    while(rear>pop)    {        _x = q[pop].x; _y = q[pop].y;        if(_x==1||_x==n||_y==1||_y==m) return 1;        for(int i = 0; i < 4; ++i)        {            _xx = _x+dx[i];            _yy = _y+dy[i];            if(vis[_xx][_yy]==0)            {                vis[_xx][_yy] = 1;                if(s[_xx][_yy]==0) q[rear++] = (Point){_xx, _yy};            }        }        ++pop;    }    return 0;}void bfs2(int x, int y){    Point q[M*M];    int rear = 1, pop = 0;    flag[x][y] = 1;    q[0] = (Point){x, y};    int _x, _y, _xx, _yy;    while(rear>pop)    {        _x = q[pop].x; _y = q[pop].y;        if(vis[_x][_y]==1) { cnt+=(s[_x][_y]-1); ++pop; continue; }        else cnt+=s[_x][_y];        for(int i = 0; i < 4; ++i)        {            _xx = _x+dx[i];            _yy = _y+dy[i];            if(_xx>=0&&_xx<=n+1&&_yy>=0&&_yy<=m+1&&flag[_xx][_yy]==0)                { flag[_xx][_yy] = 1; q[rear++] = (Point){_xx, _yy}; }        }        ++pop;    }}int main(){    int x, y;    while(~scanf("%d%d", &n, &m))    {        memset(s,0,sizeof(s));        for(int i = 1; i <= n; ++i)            for(int j = 1; j <= m; ++j)            {                scanf("%d", &s[i][j]);                if(s[i][j]==-1)                    x = i, y = j;            }        cnt = 0; vis[x][y] = 1;        memset(vis, 0,sizeof(vis));        memset(flag,0,sizeof(flag));        if(bfs(x, y)) printf("Ali Win\n");        else        {            bfs2(0,0);            if(cnt&1)                printf("Ali Win\n");            else                printf("Baba Win\n");        }    }    return 0;}