fzu1684 迷宫救美

题目链接：fzu1684

 

代码：

 

#include <iostream>#include <cmath>#include <queue>using namespace std;struct node{ int x,y,step; }tmp,head;queue <node> q;char map[25][25];int e[25][25];int dir[4][2]={-1,0,0,-1,1,0,0,1};int r,w;int energy,fx,fy;int ex,ey;void bfs(){bool flag=true;while(!q.empty()){head=q.front();q.pop();if(head.x==ex&&head.y==ey){cout<<head.step<<endl; flag=false; break;}for(int u=0;u<4;u++){tmp.x=head.x+dir[u][0];tmp.y=head.y+dir[u][1];tmp.step=head.step+1;if(tmp.x>=0&&tmp.x<r&&tmp.y>=0&&tmp.y<w)if(e[head.x][head.y]-abs(map[tmp.x][tmp.y]-map[head.x][head.y])>e[tmp.x][tmp.y]){e[tmp.x][tmp.y]=e[head.x][head.y]-abs(map[tmp.x][tmp.y]-map[head.x][head.y]);q.push(tmp);}}}if(flag)cout<<"UNLUCKY!"<<endl;}int main(){//system("color 25");while(cin>>r>>w){while(!q.empty())q.pop();//注意这句话的重要性//因为bfs里到达了目的地就退出了，并不一定清空，这样会导致wrong answer. cin>>energy>>fx>>fy;tmp.x=fx,tmp.y=fy,tmp.step=0;q.push(tmp);cin>>ex>>ey;int i,j;for(i=0;i<r;i++)for(j=0;j<w;j++){ cin>>map[i][j];e[i][j]=-1; }e[fx][fy]=energy;bfs();}return 0;}