hdu 1072 广搜

#include <iostream>
#include <queue>
using namespace std;

int map[9][9];
int n,m;
int dir[4][2]={0,1, 1,0, -1,0, 0,-1};

struct Node{
    int x,y;
    int time;
    int step;//剩余的步数
    bool operator<(const Node &a) const{
        return a.time<time;
    }
};

int bfs(int x, int y, int end_x, int end_y)
{
    priority_queue<Node>que;
    struct Node start;
    start.x=x;
    start.y=y;
    start.time=0;
    start.step=6;
    que.push(start);

    while(!que.empty())
    {
        struct Node cur=que.top();
        que.pop();
        if(cur.step==0) continue;//时间到了，结束搜索
        if(cur.step>=1 && cur.x==end_x && cur.y==end_y) return cur.time;//注意要保证剩余时间大于1
        for(int i=0; i<4; i++){
            int xtmp=cur.x+dir[i][0];
            int ytmp=cur.y+dir[i][1];
            if(map[xtmp][ytmp]==0 || xtmp<0 || xtmp>=n || ytmp<0 ||ytmp>=m) continue;
            struct Node next;
            next.x=xtmp;
            next.y=ytmp;
            next.time=cur.time+1;
            next.step=cur.step-1;
            if(map[xtmp][ytmp]==4 && next.step>=1){//注意重设时间的条件                        next.step=6;
                map[xtmp][ytmp]=0;
            }
            que.push(next);
        }
    }
    return -1;
}
int main()
{
    int t, i,j, start_x, start_y, end_x, end_y;
    cin>>t;
    while(t--)
    {
        scanf("%d%d", &n, &m);
        for(i=0; i<n; i++){
            for(j=0; j<m; j++){
                scanf("%d", &map[i][j]);
                if(map[i][j]==2){
                    start_x=i;
                    start_y=j;
                } else if(map[i][j]==3){
                    end_x=i;
                    end_y=j;
                }
            }
        }
        int result=bfs(start_x, start_y, end_x, end_y);
        cout<<result<<endl;
    }
    return 0;
}