广搜80分 第九第十个点tle

#include<cstdio>
#include<cstring>
#include<cmath>
#include<queue>
using namespace std;
int ch[4][2]={{-1,0},{0,-1},{1,0},{0,1}};
char board[1005][1005];
int book[1005][1005];
int num=10;
int n,m;
void bfs(int,int);
queue<int>h;
queue<int>l;
int main()
{
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)
            scanf("%s",&board[i][1]);
    int x,y;
    for(int i=1;i<=m;i++)
    {
            scanf("%d%d",&x,&y);
            bfs(x,y);
    }
    return 0;
}
void bfs(int u,int v)
{
     num++;     
     int step=1;
     book[u][v]=num;
     h.push(u);
     l.push(v);
     int q1,q2;
     while(!h.empty())
     {
                      for(int i=0;i<4;i++)
                      {
                              q1=h.front()+ch[i][0];
                              q2=l.front()+ch[i][1];
                              if(book[q1][q2]==num)
                                              continue ;
                              if(q1>=1 and q1<=n and q2>=1 and q2<=n and board[q1][q2]-'0'==abs(board[h.front()][l.front()]-'0'-1))
                              {
                                  book[q1][q2]=num;
                                  step++;
                                  if(step==n*n)
                                               break ;
                                  h.push(q1);
                                  l.push(q2);
                              }
                      }
                      h.pop();
                      l.pop();
                      if(step==n*n)
                                   break;
     }
     printf("%d\n",step);
}