hdu-1242 Rescue

来源：互联网发布：交易软件备案编辑：程序博客网时间：2024/06/05 04:18

本题用到了了搜索和队列，第一次将这两个加起来写，有点吃力。。。。。。

队列相关知识：http://blog.csdn.net/zxy_snow/article/details/6118988

#include<stdio.h>#include<string.h>#include<queue> #include<algorithm>using namespace std;int map[220][220];int a_x,a_y,b_x,b_y,n,m;int top[4][2]={{0,-1},{0,1},{1,0},{-1,0}};  //上下搜索的四个点 struct node{//自定义的队列 int x; int y;int step;friend bool operator < (node n1,node n2){return n2.step < n1.step;}};int judge(int x,int y){//判断执行条件 if(x < 0 || x >= n || y < 0 || y >= m)   return 1;if(map[x][y] == 1)   return 1;return 0;}int bfs(){//搜索 priority_queue<node>q;node cur,next;int i;cur.x = b_x;cur.y = b_y;cur.step = 0;map[cur.x][cur.y] = 1;q.push(cur);while(!q.empty()){cur = q.top();q.pop();if(cur.x == a_x && cur.y == a_y)    return cur.step;    for(i = 0;i < 4;i++){next.x = cur.x + top[i][0];next.y = cur.y + top[i][1];if(judge(next.x,next.y))    continue;if(map[next.x][next.y] == -1)   next.step = cur.step + 2;else   next.step = cur.step + 1;map[next.x][next.y] = 1;q.push(next);}}return -1;}int main(){int i,j,k,t;char str[220];while(~scanf("%d %d",&n,&m)){memset(map,0,sizeof(map));    for(i=0;i<n;i++){    scanf("%s",str);    for(j=0;str[j];j++){    if(str[j] == 'a'){//标记带搜索的位置     a_x = i;    a_y = j;    }    else if(str[j] == 'r'){//标记开始搜索的位置     b_x = i;    b_y = j;    }    else if(str[j] == '#')       map[i][j] = 1;//将为墙的标记为1     else if(str[j] == '.')       map[i][j] = 0;//将为道路的标记为0     else if(str[j] == 'x')       map[i][j] = -1;//将为敌人的标记为-1     }        }    int 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;}

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