HDU 1242 广搜模板

#include "stdio.h"
#include "string.h"
#include "math.h"
#include "queue"
using namespace std;

struct node
{
int x,y,step;

friend bool operator<(node n1,node n2)
{
return n2.step<n1.step;
}
};

int dir[4][2]={1,0,-1,0,0,1,0,-1};
int n,m,x_s,y_s;
int map[210][210];

int judge(int x,int y)
{
if (x<0 || x>=n || y<0 || y>=m) return 0;
if (map[x][y]==-1) return 0;

return 1;
}
int bfs()
{
priority_queue<node>q;
node cur,next;

int i;

cur.x=x_s;
cur.y=y_s;
cur.step=0;
q.push(cur);

while (!q.empty())
{
cur=q.top();
q.pop();
for (i=0;i<4;i++)
{
next.x=cur.x+dir[i][0];
next.y=cur.y+dir[i][1];

if (judge(next.x,next.y)==0) continue;

next.step=cur.step+1;
if (map[next.x][next.y]==1) next.step++;

if (map[next.x][next.y]==2) return next.step;

map[next.x][next.y]=-1;

q.push(next);
}
}
return -1;
}

int main()
{
int i,ans,j;
char str[1010];
while (scanf("%d%d",&n,&m)!=EOF)
{
getchar();
memset(map,0,sizeof(map));

for (i=0;i<n;i++)
{
gets(str);
for (j=0;str[j];j++)
{
if (str[j]=='a') { x_s=i; y_s=j;}
else if (str[j]=='r') map[i][j]=2;
else if (str[j]=='#') map[i][j]=-1;
else if (str[j]=='x') map[i][j]=1;
}
}

ans=bfs();

if (ans==-1)
printf("Poor ANGEL has to stay in the prison all his life.\n");
else
printf("%d\n",ans);
}
return 0;
}