HDU 1983 BFS&&DFS

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

int dir[4][2]={{1,0},{-1,0},{0,1},{0,-1}};

int s_x,s_y,n,m,t;
char str[11][11];

struct node
{
int x,y,step,key;
};
int bfs()
{
queue<node>q;
node cur,next;
int i;
int hash[11][11][2];

cur.x=s_x;
cur.y=s_y;
cur.step=0;
cur.key=0;
q.push(cur);
memset(hash,0,sizeof(hash));
hash[s_x][s_y][0]=1;

while (!q.empty())
{
cur=q.front();
q.pop();
if (cur.step>=t) return -1;

for (i=0;i<4;i++)
{
next.x=cur.x+dir[i][0];
next.y=cur.y+dir[i][1];
if (next.x<0 || next.y<0 || next.x>=n || next.y>=m) continue;
if (str[next.x][next.y]=='#') continue;
next.step=cur.step+1;
next.key=cur.key;
if (str[next.x][next.y]=='J')
next.key=1;
if (hash[next.x][next.y][next.key]==1) continue;
hash[next.x][next.y][next.key]=1;
q.push(next);
if (str[next.x][next.y]=='E' && next.key==1) return 1;
}
}
return -1;
}

int dfs(int k)
{
int i,j;
char ch;
if (k==0)
return bfs();

for (i=0;i<n;i++)
for (j=0;j<m;j++)
if (str[i][j]=='J' || str[i][j]=='.')
{
ch=str[i][j];
str[i][j]='#';
if (dfs(k-1)==-1)
return -1;
str[i][j]=ch;
}
return 1;
}
int main()
{
int Case,i,j;
scanf("%d",&Case);
while (Case--)
{
scanf("%d%d%d",&n,&m,&t);
for (i=0; i<n; i++)
{
scanf("%s",str[i]);
for (j=0; j<m; j++)
if(str[i][j]=='S')
{
s_x=i;
s_y=j;
break;
}
}

if (bfs()==-1)
{
printf("0\n");
continue;
}

if (dfs(1)==-1)
printf("1\n");
else
if (dfs(2)==-1)
printf("2\n");
else
if (dfs(3)==-1)
printf("3\n");
else
printf("4\n");
}
return 0;
}