迷宫最短路径 广度优先搜索—C

从迷宫的起点到终点的最短路径，用广度优先搜索

#include
struct node
{
    int x;
    int y;
    int s;
};
int main()
{
    int i,j,k,startx,starty,tx,ty,flag=0;
    int n,m,p,q,min=99999999;
    int a[100][100],book[100][100];
    struct node queue[100],t;
    int head,tail;
    int next[4][2]={{0,1},{1,0},{0,-1},{-1,0}};


    scanf("%d%d",&n,&m);
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
            scanf("%d",&a[i][j]);


    scanf("%d%d%d%d",&startx,&starty,&p,&q);
    head=1;
    tail=1;
    queue[tail].x=startx;
    queue[tail].y=starty;
    queue[tail].s=0;
    tail++;
    book[startx][starty]=1;
    while(headqueue[head];
        for(k=0;k<=3;k++)
        {
           tx=t.x+next[k][0];
           ty=t.y+next[k][1];
           if(tx<1||tx>n||ty<1||ty>m)
               continue;
           if(a[tx][ty]==0&&book[tx][ty]==0)
           {
               book[tx][ty]=1;
               queue[tail].x=tx;
               queue[tail].y=ty;
               queue[tail].s=t.s+1;
               tail++;
           }
           if(tx==p&&ty==q)
            {
                flag=1;
                break;
            }
        }
        if(flag==1)
            break;
        head++;
  }
    printf("%d",queue[tail-1].s);
    return 0;
}